Documents published in 2019 : Scipedia

Informative treatment of the mapuches in the newspaper El Mercurio. A content analysis based on the Framing Theory
C. Valle-Rojas, M. Ruiz, F. Verdú, F. Silva-Layera

correspondencias & análisis (2019). 9

Abstract
This paper analyzes the information treatment of the Mapuche people in the newspaper El Mercurio during two periods. First, between 1950 and 1973 (twentieth century); and second, during the years 2010, 2013 and 2014, (21st century). To this end, a corpus of 340 journalistic texts has been selected, of which 147 correspond to the 20th century (1950-1970) and 193, to the 21st century (2010, 2013-2014). The analysis shows that most of the frames are linked to conflicts, criminal prosecutions and arson attacks; so that El Mercurio prioritizes connotations and negative events to inform about the Mapuche indigenous people.
Abstract
This paper analyzes the information treatment of the Mapuche people in the newspaper El Mercurio during two periods. First, between 1950 and 1973 (twentieth century); and [...]
- 6
- read
The contribution of social communication to projects of rehabilitation of water and sanitation networks: The case of Sedapal Project Lote 3
W. Alva

correspondencias & análisis (2019). 8

Abstract
This paper focus on implementation of communication strategies developed in the Rehabilitation of Potable Water and Sewerage Network Lote 3 project, executed between 2013 and 2014 in the district of Comas, north of Lima-Peru, and belonging to the Servicio de Agua Potable y Alcantarillado de Lima (SEDAPAL), company responsible for water and sewage in Lima. As a result, it could be observed that the implementation of a diagnosis of perceptions, the communication plan and the communication and education products allowed to facilitate the design of messages according to the context of the project, taking into account the speeches of the users against and in favor of the project, as well as the objectives sought by the executing company.
Abstract
This paper focus on implementation of communication strategies developed in the Rehabilitation of Potable Water and Sewerage Network Lote 3 project, executed between 2013 [...]
- 2
- read
Public Relations in electoral campaigns
A. Zepeda

correspondencias & análisis (2019). 7

Abstract
The essay makes a description of the strategical role the play public relations during electoral campaigns. In the beginning, the essay conceptualizes public relations and its connection with political campaigns. It is argued that make an electoral campaign imply a public relation activity with the objective of knowing the voters and make up different political strategies to get their votes and, consequently, avoid the opposition can win the political power. It is concluded that the successful in a political campaigns depends on the creative, intelligent and innovative use of public relations.
Abstract
The essay makes a description of the strategical role the play public relations during electoral campaigns. In the beginning, the essay conceptualizes public relations and [...]
- 3
- read
Transmedia Storytelling and Construction of Fictional Worlds: Aliados Series as Case Study
T. Atarama-Rojas

correspondencias & análisis (2019). 6

Abstract
This paper explores the contributions of transmedia storytelling in the construction of fictional worlds, in an attempt to detect the narrative elements that strengthen the bond of the audience with the fictional world. The study shows that based on the solid construction of the poetics of a story, transmedia storytelling can enrich the engagement with a large audience. To prove this, we analyze the narrative elements and the transmedia strategies of the series Aliados, produced by Cris Morena Group and broadcasted in Latin America and countries in Europe
Abstract
This paper explores the contributions of transmedia storytelling in the construction of fictional worlds, in an attempt to detect the narrative elements that strengthen the [...]
- 8
- read
Strategy and management, the foundations of any successful brand
S. Escalada

correspondencias & análisis (2019). 5

Abstract
When analyzing any branding work we tend to simplify a process that by its nature is enormously complex and multidisciplinary. There is an important current of opinion that tends to reduce the creation of a brand to its logo or to the group of elements that will articulate the visual identity in a sort of cosmetic image, or purely aesthetic. Either by understanding branding as a superficial expense and not as a strategic investment, due to ignorance of the discipline, short-sightedness, lack of means and / or professionals or, by a mixture of all these factors, the brands themselves devalue in many cases from the moment they make the decision not to face their construction in a studied way, serious and coherent.
Abstract
When analyzing any branding work we tend to simplify a process that by its nature is enormously complex and multidisciplinary. There is an important current of opinion that [...]
- 3
- read
Andragogy and training of entrepreneurs at UNESR Bolívar
M. Doubront

Petronila Liz Contreras Yalico's personal collection (2019). 6

Abstract
Given the complex crisis experienced by Venezuela, which has provoked a systematic defection of university students, there is a need to structure a training plan for entrepreneurs, to create new businesses, where youth have a leading role, strengthening a culture of entrepreneurship compatible with Andragogical, participatory and flexible philosophy of Universidad Nacional Experimental Simón Rodríguez (UNESR).
Abstract
Given the complex crisis experienced by Venezuela, which has provoked a systematic defection of university students, there is a need to structure a training plan for entrepreneurs, [...]
- 14
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Vulnerability of social communication students. A case study
P. Echeverry

Petronila Liz Contreras Yalico's personal collection (2019). 7

Abstract
This article start with a research completed in 2018, whose goal was to identify situations and causes of physical, emotional, social and economic vulnerability of the students of the Social Communication´s program. In pursuit of this aim, four discussion groups, 125 surveys shaped with 49 closed questions each, provided the information for the analysis. The results of the research, enabled the identification of some socioeconomic characteristics of the students, such as that the program average student lives in low-middle class neighborhoods, does not get to have three proper meals a day and depends on his family to pay their student fees and their sustenance. The research also showed that belonging to the LGBTIQ+ population, parenting, and financial difficulties, represent some bigger student vulnerability conditions which impact in the quality of the training environment and the forming process itself.
Abstract
This article start with a research completed in 2018, whose goal was to identify situations and causes of physical, emotional, social and economic vulnerability of the students [...]
- 12
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El Caso Mundial y El Caso Criminal, cabeceras del nuevo semanario de sucesos que surge en España tras la desaparición de El Caso (1952-1987)
R. Cárcela, P. CONTRERAS YALICO

Petronila Liz Contreras Yalico's personal collection (2019). 8

Abstract
El artículo analiza “El Caso Mundial” y “El Caso Criminal”, ambos periódicos de eventos que surgieron en España después de la desaparición de “El Caso” (Madrid, 1952-1987), y fue publicado por el empresario y periodista Joaquín Abad. . Se ha realizado poca investigación en este periódico que llegó a llenar el vacío dejado por 'El Caso', dirigido por Eugenio Suárez. Las fuentes consultadas muestran que se trata realmente de una nueva publicación periodística, similar a la original, pero diferente. Por lo tanto, no puede considerarse una segunda etapa. Se imprimió y distribuyó desde Almería durante diez años (1987-1997), aunque tuvo un alcance nacional. Su estilo informativo, contenido, directores y las causas que llevaron a su finalización el 24 de septiembre de 1997.
Abstract
El artículo analiza “El Caso Mundial” y “El Caso Criminal”, ambos periódicos de eventos que surgieron en España después [...]
- 5
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El Caso Mundial and El Caso Criminal, new weekly papers in Spain after the disappearance of El Caso (1952-1987)
R. Cárcela

correspondencias & análisis (2019). 3

Abstract
The paper analyses “El Caso Mundial” and “El Caso Criminal”, both of them event newspapers that emerged in Spain after the disappearance of "El Caso" (Madrid, 1952-1987), and was published by the businessman and journalist Joaquín Abad. Few research has been done on this newspaper that came to fill the gap left by "El Caso", directed by Eugenio Suárez. The sources consulted show that it was really a new journalistic publication, similar to the original one, but different. Therefore, it cannot be considered a second stage. It was printed and distributed from Almería for ten years (1987-1997), although it had a national scope. His informative style, content, directors and the causes that led to its completion on September 24, 1997.
Abstract
The paper analyses “El Caso Mundial” and “El Caso Criminal”, both of them event newspapers that emerged in Spain after the disappearance of "El [...]
- 3
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The concept of Chronicle: An overview from Social and Human Sciences contributions
J. Altamar

correspondencias & análisis (2019). 2

Abstract
We reflect on the concept of the Latin American chronicle from the understanding that to build it, testimonial is not enough, but that additional criteria must be taken into account from the theories of narration, literature, social psychology, anthropology symbolic and ethnography. To this are added the contributions of the journalistic-literary tendencies of the North American style, which, in turn, were nourished by the approaches of the nineteenth-century European realist novel. The result is a concept in which the chronicle is located as a genre of a creative and narrative nature, with a particular voice and tone of marked literary influence, with which the reality that is recreated -be it character, place, situation or event-, both from factors of typical interest from journalism, as from the meaningful everyday life.
Abstract
We reflect on the concept of the Latin American chronicle from the understanding that to build it, testimonial is not enough, but that additional criteria must be taken into [...]
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Manipulación fotográfica y credibilidad del medio periodístico a través de la fotografía
G. García

correspondencias & análisis (2019). 4

Abstract
El presente estudio tiene como objetivo conocer de qué manera la manipulación fotográfica se relaciona con la credibilidad del medio periodístico a través de la fotografía publicada en el diario Los Angeles Times, referida a la Segunda Guerra del Golfo en el 2003. El diseño de investigación es no experimental, con corte trasversal; tipo de investigación aplicativa; nivel de investigación descriptivo, correlacional y comparativo; método de investigación inductivo, deductivo, analítico, estadístico y hermenéutico. Con unidades de análisis y muestras de población de estudiantes de Lima y Nueva York, se confirma la hipótesis general que hace referencia a la relación significativa entre la manipulación fotográfica y la credibilidad del medio periodístico, al tomarse en consideración el material fotográfico publicado en el diario Los Angeles Times durante la Segunda Guerra del Golfo en el 2003.
Abstract
El presente estudio tiene como objetivo conocer de qué manera la manipulación fotográfica se relaciona con la credibilidad del medio periodístico [...]
- 93
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Informative treatment of the mapuches in the newspaper El Mercurio. A content analysis based on the Framing Theory
C. Valle-Rojas, F. Verdú, F. Silva-Layera

Petronila Liz Contreras Yalico's personal collection (2019). 5

Abstract
This paper analyzes the information treatment of the Mapuche people in the newspaper El Mercurio during two periods. First, between 1950 and 1973 (twentieth century); and second, during the years 2010, 2013 and 2014, (21st century). To this end, a corpus of 340 journalistic texts has been selected, of which 147 correspond to the 20th century (1950-1970) and 193, to the 21st century (2010, 2013-2014). The analysis shows that most of the frames are linked to conflicts, criminal prosecutions and arson attacks; so that El Mercurio prioritizes connotations and negative events to inform about the Mapuche indigenous people.
Abstract
This paper analyzes the information treatment of the Mapuche people in the newspaper El Mercurio during two periods. First, between 1950 and 1973 (twentieth century); and [...]
- 23
- read
The contribution of social communication to projects of rehabilitation of water and sanitation networks: The case of Sedapal Project Lote 3
W. Alva

Correspondencias & análisis (2019). n°9

Abstract
This paper focus on implementation of communication strategies developed in the Rehabilitation of Potable Water and Sewerage Network Lote 3 project, executed between 2013 and 2014 in the district of Comas, north of Lima-Peru, and belonging to the Servicio de Agua Potable y Alcantarillado de Lima (SEDAPAL), company responsible for water and sewage in Lima. As a result, it could be observed that the implementation of a diagnosis of perceptions, the communication plan and the communication and education products allowed to facilitate the design of messages according to the context of the project, taking into account the speeches of the users against and in favor of the project, as well as the objectives sought by the executing company.
Abstract
This paper focus on implementation of communication strategies developed in the Rehabilitation of Potable Water and Sewerage Network Lote 3 project, executed between 2013 [...]
- 10
- read
Public Relations in electoral campaigns
A. Zepeda

Correspondencias & análisis (2019). n°9

Abstract
The essay makes a description of the strategical role the play public relations during electoral campaigns. In the beginning, the essay conceptualizes public relations and its connection with political campaigns. It is argued that make an electoral campaign imply a public relation activity with the objective of knowing the voters and make up different political strategies to get their votes and, consequently, avoid the opposition can win the political power. It is concluded that the successful in a political campaigns depends on the creative, intelligent and innovative use of public relations.
Abstract
The essay makes a description of the strategical role the play public relations during electoral campaigns. In the beginning, the essay conceptualizes public relations and [...]
- 9
- read
Transmedia Storytelling and Construction of Fictional Worlds: Aliados Series as Case Study
T. Atarama-Rojas

Petronila Liz Contreras Yalico's personal collection (2019). 2

Abstract
This paper explores the contributions of transmedia storytelling in the construction of fictional worlds, in an attempt to detect the narrative elements that strengthen the bond of the audience with the fictional world. The study shows that based on the solid construction of the poetics of a story, transmedia storytelling can enrich the engagement with a large audience. To prove this, we analyze the narrative elements and the transmedia strategies of the series Aliados, produced by Cris Morena Group and broadcasted in Latin America and countries in Europe.
Abstract
This paper explores the contributions of transmedia storytelling in the construction of fictional worlds, in an attempt to detect the narrative elements that strengthen the [...]
- 4
- read
Strategy and management, the foundations of any successful brand
S. Escalada

Correspondencias & análisis (2019). n°9

Abstract
When analyzing any branding work we tend to simplify a process that by its nature is enormously complex and multidisciplinary. There is an important current of opinion that tends to reduce the creation of a brand to its logo or to the group of elements that will articulate the visual identity in a sort of cosmetic image, or purely aesthetic. Either by understanding branding as a superficial expense and not as a strategic investment, due to ignorance of the discipline, short-sightedness, lack of means and / or professionals or, by a mixture of all these factors, the brands themselves devalue in many cases from the moment they make the decision not to face their construction in a studied way, serious and coherent.
Abstract
When analyzing any branding work we tend to simplify a process that by its nature is enormously complex and multidisciplinary. There is an important current of opinion that [...]
- 5
- read
2nd FIBRESHIP WORKSHOP - Overall description of the FIBRESHIP project
A. Jurado

Open Access Repository of the FIBRESHIP project (2019). 12

Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP project offered to the participants a chance to discuss the different composite materials solutions for shipbuilding as well as learn more about the latest technological advances of FIBRESHIP Project related to design, construction and operation of ships integrally built in composite materials. FIBRESHIP Consortium is looking for a niche in the future shipping market through promoting changes in the regulatory framework of IMO and generating guidelines and methodologies for designing, building and operating large-length vessels, laying the foundations of a new market based on composites technology in shipbuilding and shipping. This presentation introduces the Fibreship project, which addresses the feasibility of the construction of large-length vessels using uniquely lightweight composite materials in their structures. Alfonso explained the significant advantages of the massive application of lightweight composite materials in design, construction and operation of large-length ships. The main challenge of this project is to generate a discussion in regulatory bodies through the advances and developments reached in the project in order to promote new rules and regulations that allows the integral construction of ships over 500 GT (approx. 50 meters in length) in FRP materials, which will result in the development of a new European market based on the construction of lightweight ships.
Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP [...]
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2nd FIBRESHIP WORKSHOP - Durability of sandwich structures, fatigue testing and recent advances in fire strength modeling
P. Casari

Open Access Repository of the FIBRESHIP project (2019). 6

Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP project offered to the participants a chance to discuss the different composite materials solutions for shipbuilding as well as learn more about the latest technological advances of FIBRESHIP Project related to design, construction and operation of ships integrally built in composite materials. FIBRESHIP Consortium is looking for a niche in the future shipping market through promoting changes in the regulatory framework of IMO and generating guidelines and methodologies for designing, building and operating large-length vessels, laying the foundations of a new market based on composites technology in shipbuilding and shipping. This presentation shows interesting results about the mechanical behaviour of sandwich structures under cyclic fatigue stresses. To address this study, a wide variety of experimental tests as per example digital image correlation or tomography analysis were carried out to investigate the failure modes of these materials. Moreover, the fire behaviour of these sandwich structures is investigated using advanced simulation tools based on finite element analysis.
Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of [...]
- 22
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2nd FIBRESHIP WORKSHOP - Breakout Session 1 - Materials
X. Martinez

Open Access Repository of the FIBRESHIP project (2019). 9

Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP project offered to the participants a chance to discuss the different composite materials solutions for shipbuilding as well as learn more about the latest technological advances of FIBRESHIP Project related to design, construction and operation of ships integrally built in composite materials. FIBRESHIP Consortium is looking for a niche in the future shipping market through promoting changes in the regulatory framework of IMO and generating guidelines and methodologies for designing, building and operating large-length vessels, laying the foundations of a new market based on composites technology in shipbuilding and shipping. This presentation explains the development of a new methodology for the selection of composites for marine applications, which has been developed within the FIBRESHIP project. This methodology is based on an extensive characterization of the mechanical and fire properties of the potential composites which would be used by designers in the construction of new fibre ships. On top of that, Xavier presented a new type of structural joining connections between the modules and composite sections of the ship which facilitates the structure disassembly.
Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP [...]
- 16
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2nd FIBRESHIP WORKSHOP - RAMSSES demo case
E. Billaudeau

Open Access Repository of the FIBRESHIP project (2019). 11

Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP project offered to the participants a chance to discuss the different composite materials solutions for shipbuilding as well as learn more about the latest technological advances of FIBRESHIP Project related to design, construction and operation of ships integrally built in composite materials. FIBRESHIP Consortium is looking for a niche in the future shipping market through promoting changes in the regulatory framework of IMO and generating guidelines and methodologies for designing, building and operating large-length vessels, laying the foundations of a new market based on composites technology in shipbuilding and shipping. In the first section of his presentation, the main objectives of the RAMSSES project are explained (reduction of the weight using multifunctional materials, selection of optimum materials and structural connections for the construction of lightweight ships, etc.). In the second one, it is explained in detail the technical progresses and the experimental and numerical results obtained the in the project up to now.
Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP [...]
- 22
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2nd FIBRESHIP WORKSHOP - At the forefront of technology
T. Iturgaiz

Open Access Repository of the FIBRESHIP project (2019). 7

Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP project offered to the participants a chance to discuss the different composite materials solutions for shipbuilding as well as learn more about the latest technological advances of FIBRESHIP Project related to design, construction and operation of ships integrally built in composite materials. FIBRESHIP Consortium is looking for a niche in the future shipping market through promoting changes in the regulatory framework of IMO and generating guidelines and methodologies for designing, building and operating large-length vessels, laying the foundations of a new market based on composites technology in shipbuilding and shipping. In this presentation, Txuma Iturgáiz on behalf of MTorres introduced the field of activity of his company which is focused on the development of new innovative machines with a high level of automatization for manufacturing and testing composite laminates. Txuma suggested that the most advanced technologies for composite manufacturing can be applied for the shipyards in the construction of a new generation of lightweight ships with the advantages of reasonable cost, flexibility and outstanding quality, extrapolating the advances reached in aeronautical and automotive sectors.
Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop [...]
- 24
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2nd FIBRESHIP WORKSHOP - Breakout Session 2 - Computational Analysis Tools
J. García-Espinosa

Open Access Repository of the FIBRESHIP project (2019). 8

Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP project offered to the participants a chance to discuss the different composite materials solutions for shipbuilding as well as learn more about the latest technological advances of FIBRESHIP Project related to design, construction and operation of ships integrally built in composite materials. FIBRESHIP Consortium is looking for a niche in the future shipping market through promoting changes in the regulatory framework of IMO and generating guidelines and methodologies for designing, building and operating large-length vessels, laying the foundations of a new market based on composites technology in shipbuilding and shipping. This presentation explains the development of a new software suite with a wide variety of ad-hoctools to simulate the structural and fire performance of the lightweight composite ships developed within the FIBRESHIP project. The computational analysis tool is based on a fast-numerical software which can be used for the simulation of fatigue, fire diagnosis, thermal propagation, hydro-structural analysis and so on. A Betha version of the developed software suite of this numerical tool is available for the partners of the project.
Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP [...]
- 18
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2nd FIBRESHIP WORKSHOP - Breakout Session 3 - Production / Demonstrator
J. Rasmussen, E. Waldura

Open Access Repository of the FIBRESHIP project (2019). 5

Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP project offered to the participants a chance to discuss the different composite materials solutions for shipbuilding as well as learn more about the latest technological advances of FIBRESHIP Project related to design, construction and operation of ships integrally built in composite materials. FIBRESHIP Consortium is looking for a niche in the future shipping market through promoting changes in the regulatory framework of IMO and generating guidelines and methodologies for designing, building and operating large-length vessels, laying the foundations of a new market based on composites technology in shipbuilding and shipping. This presentation is focussed on the development of efficient production methodologies and automatized processes which can be efficiently used for the construction of large-length composite ships by the shipyards. Furthermore, it describes the technical feasibility of the construction of the demonstrator of the project using exclusively lightweight composite materials.
Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP [...]
- 28
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2nd FIBRESHIP WORKSHOP - Breakout Session 4 - Regulatory and Standardisation
R. Devalapalli, S. Paboeuf

Open Access Repository of the FIBRESHIP project (2019). 10

Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP project offered to the participants a chance to discuss the different composite materials solutions for shipbuilding as well as learn more about the latest technological advances of FIBRESHIP Project related to design, construction and operation of ships integrally built in composite materials. FIBRESHIP Consortium is looking for a niche in the future shipping market through promoting changes in the regulatory framework of IMO and generating guidelines and methodologies for designing, building and operating large-length vessels, laying the foundations of a new market based on composites technology in shipbuilding and shipping. This presentation is dedicated to the strategies of regulatory and standardization activities of the project, mainly focused on the fire challenges related to the use of composites in the shipping industry. Reddy Devalapalli (Lloyd’s Register of Shipping) explained that a presentation in collaboration with RAMSSES project is being prepared for the next SDC of IMO in February 2020 as well as a info paper, to promote changes in the current regulatory frameworks which limit the use of Fibre Reinforced Plastic elements in the construction of large-length ship structures. In addition, Stephane Pabeouf from Bureau Veritas described the development of new performance criteria which will attempt to deal with the fire safety issues and structural performance of the new lightweight ships, being an essential part of the FIBRESHIP project.
Abstract
Presentation held at the second public workshop of the FIBRESHIP project, held at La Ciotat, France, on 25th of June 2019. The second public workshop of the FIBRESHIP [...]
- 17
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Meshless method with ridge basis functions for two-flow domain model
X. Qin, K. Li, G. Hu

Revista Mexicana de Métodos Numéricos (2019). Vol. 3, 3

Abstract
A meshless method with ridge basis functions for solving the 2D two-flow domain model problem is proposed in this paper, which is using ridge basis functions to construct the approximate functions, and using collocation method to discretize the governing equation. The existence and uniqueness of the solution to the mothod is analyzed. Compared with the traditional finite difference method, the new method reduces the calculation error. Numerical results show that the proposed method is convergent and can improve the error precision.
Abstract
A meshless method with ridge basis functions for solving the 2D two-flow domain model problem is proposed in this paper, which is using ridge basis functions to construct [...]
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A Second Order Semi-Lagrangian Particle Finite Element Method for Fluid Flows
J. Colom Cobb, J. García-Espinosa, B. Servan Camas, P. Nadukandi

Computational Particle Mechanics (2020). 7, 3–18

Abstract
In this paper, a second order SL-PFEM scheme for solving the incompressible Navier-Stokes equations is presented. This scheme is based on the second order velocity Verlet algorithm, which uses an explicit integration for the particle’s trajectory and an implicit integration for the velocity. The algorithm is completed with a predictor-multicorrector scheme for the integration of the velocity correction using the Finite Element Method. A second order projector based on least squares is used to transfer the intrinsic variables information from the particles onto the background mesh, while a second order interpolation scheme is used to transfer the accelerations from the mesh to the particles. Convergence analyses are carried out to assess the second order convergence.
Abstract
In this paper, a second order SL-PFEM scheme for solving the incompressible Navier-Stokes equations is presented. This scheme is based on the second order velocity Verlet [...]
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An implicit unsteady hydraulic solver for suspended cuttings transport in managed pressure wells
R. Flores, R. Ortega, A. Ilin, D. Simpkins, E. Oñate

Computational Particle Mechanics (2019). Vol. 6 (2), pp 163–175

Abstract
We present a simulation tool for transient events in complex hydraulic networks. The code includes modelling of the transport of suspended cuttings in near-vertical wells. An unstructured finite volume formulation with implicit time integration has been chosen. The unconditional stability of the integrator makes the method suitable for the simulation of transient events over a wide range of characteristic timescales. It handles both very fast transients (e.g. fluid hammer events) and the long-term evolution of the well (e.g. hole cleaning operations). The software has been developed to address the need of the oil industry for a robust and efficient predictive tool allowing effective well control in managed pressure drilling operations. The physical modelling follows the standard practices accepted by the industry (e.g. mud rheology computations). The mathematical foundation of the algorithm is described followed by validation cases that illustrate its capabilities and accuracy. Finally, a practical industrial application example is provided to demonstrate the real-world performance of the software.
Abstract
We present a simulation tool for transient events in complex hydraulic networks. The code includes modelling of the transport of suspended cuttings in near-vertical wells. [...]
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Effect of the integration scheme on the rotation of non-spherical particles with the discrete element method
J. Irazábal González, F. Salazar, M. Santasusana, E. Oñate

Computational Particle Mechanics (2019). Vol. 6 (4), pp 545–559

Abstract
The discrete element method (DEM) is an emerging tool for the calculation of the behaviour of bulk materials. One of the key features of this method is the explicit integration of the motion equations. Explicit methods are rapid, at the cost of a limited time step to achieve numerical stability. First- or second-order integration schemes based on a Taylor series are frequently used in this framework and shown to be accurate for the translational and rotational motion of spherical particles. However, they may lead to relevant inaccuracies when non-spherical particles are used since the orientation implies a modification in the second-order inertia tensor in the inertial reference frame. Specific integration schemes for non-spherical particles have been proposed in the literature, such as the fourth-order Runge–Kutta scheme presented by Munjiza et al. and the predictor–corrector scheme developed by Zhao and van Wachem which applies the direct multiplication algorithm for integrating the orientation. In this work, both methods are adapted to be used together with a velocity Verlet scheme for the translational integration. The performance of the resulting schemes, as well as that of the direct integration method, is assessed, both in benchmark tests with analytical solution and in real-scale problems. The results suggest that the fourth-order Runge–Kutta and the Zhao and van Wachem schemes are clearly more accurate than the direct integration method without increasing the computational time.
Abstract
The discrete element method (DEM) is an emerging tool for the calculation of the behaviour of bulk materials. One of the key features of this method is the explicit integration [...]
- 13
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A unified Lagrangian formulation for solid and fluid dynamics and its possibility for modelling submarine landslides and their consequences
X. Zhang, E. Oñate, S. Galindo, J. Bleyer, K. Krabbenhoft

Comput. Methods Appl. Mech. Engrg., (2019). Vol. 343, pp. 314-338

Abstract
Consequences of submarine landslides include both their direct impact on offshore infrastructure, such as subsea electric cables and gas/oil pipelines, and their indirect impact via the generated tsunami. The simulation of submarine landslides and their consequences has been a long-standing challenge majorly due to the strong coupling among sliding sediments, seawater and infrastructure as well as the induced extreme material deformation during the complete process. In this paper, we propose a unified finite element formulation for solid and fluid dynamics based on a generalised Hellinger–Reissner variational principle so that the coupling of fluid and solid can be achieved naturally in a monolithic fashion. In order to tackle extreme deformation problems, the resulting formulation is implemented within the framework of the particle finite element method. The correctness and robustness of the proposed unified formulation for single-phase problems (e.g. fluid dynamics problems involving Newtonian/Non-Newtonian flows and solid dynamics problems) as well as for multi-phase problems (e.g. two-phase flows) are verified against benchmarks. Comparisons are carried out against numerical and analytical solutions or experimental data that are available in the literature. Last but not least, the possibility of the proposed approach for modelling submarine landslides and their consequences is demonstrated via a numerical experiment of an underwater slope stability problem. It is shown that the failure and post-failure processes of the underwater slope can be predicted in a single simulation with its direct threat to a nearby pipeline and indirect threat by generating tsunami being estimated as well.
Abstract
Consequences of submarine landslides include both their direct impact on offshore infrastructure, such as subsea electric cables and gas/oil pipelines, [...]
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Modeling polycrystalline materials with elongated grains
I. Pérez, M. Farias, M. Castro, R. Roselló, C. Morfa, L. Medina, E. Oñate

Int J Numer Methods Eng. (2019). Vol. 118 (3), pp. 121-131

Abstract
A novel algorithm to reproduce the arrangement of grains in polycrystalline materials was recently published by the authors. In this original approach, a dense package of circles (or spheres) with the same distribution as the grains is generated to produce a set of Voronoi cells that are later modified to Laguerre cells representing the original structure. This algorithm was successfully applied to materials with somewhat equidimensional grains; however, it fails for long‐shaped grains. In this paper, modifications are provided in order to overcome these drawbacks. This is accomplished by moving each vertex of the Voronoi cells in such a way that the vertex should be equidistant from the particles with respect to the Euclidean distance. The algorithm is applied to packages of ellipses and spherocylinders in 2D. An example for a package of spheres is also provided to illustrate the application for a simple 3D case. The adherence between the generated packages and the corresponding tessellations is verified by means of the Jaccard coefficient (J). Several packages are generated randomly and the distribution of J coefficients is investigated. The obtained values satisfy the theoretical restraints and the quality of the proposed algorithm is statistically validated.
Abstract
A novel algorithm to reproduce the arrangement of grains in polycrystalline materials was recently published by the authors. In this original approach, a dense package of [...]
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Advances in particle packing algorithms for generating the medium in the Discrete Element Method
C. Recarey, I. Pérez, R. Roselló, M. Muniz, E. Hernández, R. Giraldo, E. Oñate

Computer Methods in Applied Mechanics and Engineering (2019). Vol. 345, pp. 336-362

Abstract
Several theoretical contributions in order to establish a particle packing methodology are presented. In this respect, a generic formulation of a new method for packing particles based on a constructive advancing front method, which uses Monte Carlo techniques for the generation of particle dimensions, is also shown. The method can be used to obtain virtual dense packings of particles with several geometrical shapes. It employs continuous, discrete and empirical statistical distributions in order to generate the dimensions of particles. The packing algorithm is very flexible and allows alternatives for: 1- The direction of the advancing front (inwards or outwards), 2- The selection of the local advancing front, 3- The method for placing a mobile particle in contact with others and 4- The overlap checks. The algorithm also allows obtaining highly porous media when it is slightly modified. Practical applications of the formulations are presented in the end of this paper.
Abstract
Several theoretical contributions in order to establish a particle packing methodology are presented. In this respect, a generic formulation of a new method for packing [...]
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Numerical Analysis of Axisymmetric Solids by the Finite Element Method: Use in Concrete, Steel and Mixed Steel-Concrete Elements
T. Ferreira

Numerical Analysis of Axisymmetric Solids by the Finite Element Method Use in Concrete, Steel and Mixed Steel-Concrete Elements (2019). 1
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COSMOLOGÍA N-DIMENSIONAL DE TIPO KALUZA-KLEIN EN EL VACÍO
C. Leal, C. Rodríguez

(Select a year).

Abstract
In this thesis starting from a 7-dimensional metric for the three cases: plane, elliptical and hyperbolic, we obtained the ecs. of Einstein 7-D. Then, solutions to these equations were corroborated in a vacuum. And finally I found a solution for ecs. 6-D with density of matter. En esta tesis partiendo de una métrica 7-dimensional para los tres casos: plano, elíptico e hiperbólico, se obtuvieron las ecs. de Einstein 7-D. Luego se corroboraron soluciones a dichas ecuaciones en el vacío. Y por último encontré una solución para las ecs. 6-D con densidad de materia.
Abstract
In this thesis starting from a 7-dimensional metric for the three cases: plane, elliptical and hyperbolic, we obtained the ecs. of Einstein 7-D. Then, solutions [...]
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Insertion problems in geomechanics with the particle finite element method
L. Monforte, M. Arroyo, J. Carbonell, A. Gens

Monograph CIMNE (2018). M185

Abstract
This work develops a numerical technique in which the Particle Finite Element method is applied to simulate solid intrusion problems in Geotechnical Engineering. The work describes the numerical developments that made the method functional and showcases its potential with various application problems. New numerical developments include: integration schemes for large-strain, elasto-plastic constitutive models, novel integration methods for rigid body contact constraints and stabilized mixed formulations for single-phase and two-phase problems. An explicit stress integration scheme is developed for elasto-plastic, large-strain constitutive models using a multiplicative split of the deformation gradient. This scheme uses adaptive substepping and a yield violation drift correction technique. Rigid bodies with pre-specified shape and motion may be modeled. Contact constraints are introduced using a penalty method in which tangential behavior is treated with an elasto-plastic analogy. This elasto-plastic contact model is integrated by means of an implicit integration technique; an alternative scheme using the Implex algorithm is also described and assessed. Low-order (linear) elements are employed to speed computation. These elements may suffer volumetric locking in quasi-incompressible conditions. For soils, such conditions appear under undrained loading or at critical state. To alleviate this problem, mixed formulations are developed and stabilization techniques are applied. Two different three-field mixed formulations for the coupled hydro-mechanical problem are presented, adding either the effective pressure or the Jacobian as nodal variables to the solid skeleton displacement and water pressure. Stabilization terms are used in the mass conservation equation of the biphasic medium and in the rest of scalar equations. Several mixed formulations are also implemented for the simplified single-phase problem, which approximates saturated soil behavior under undrained conditions. The first application examples are three total stress problems: indentation of a rigid strip footing, T-Bar motion and a rough cone penetration test. All are frequently used benchmark problems; they allow to compare the performance of the developed numerical scheme with other techniques. It appears that the numerical strategy followed by PFEM, obtains similar results than those attained with alternative numerical methods with significant savings in computational efforts. A total stress approach is also used in a parametric study of tube sampling in clay. The parameters explored include sampler geometry (round-tipped or beveled cutting shoes; outer diameter to wall thickness ratios); constitutive parameters, roughness factor and boundary conditions are studied. Outputs are analyzed in terms of classical sampling disturbance measures: the centerline strain path and the specific recovery ratio. The results show good agreement with experimental evidence and question the frequently accepted reference role of Strain Path method solutions. The set of simulations in which a rough interface behavior is considered has been used to assess the theory proposed by Paikowsky and Whitman (1990) to predict the occurrence of a plug inside of an open-ended pile. The numerical results obtained here corroborate this theory: a plug inside of the tube is formed once the mobilized forces are equal to those that would mobilize a smooth closed-ended pile. Indeed, the failure mechanism that prevails during the penetration of a plugged tube is coincident with that of a closed-ended pile. The last analysis of this work is the hydro-mechanical simulation of the cone penetration test in a Modified Cam Clay soil. A parametric analysis covers the effect of the permeability of the soil -from drained to undrained conditions- and the interface friction angle. The effect of these parameters on the cone resistance, sleeve friction and pore pressure at three potential measurement points is fully characterized. These numerical results are used to assess several techniques to estimate the permeability of soils from CPTu testing. Special attention is paid to on-the-fly techniques, in which permeability could be directly estimated from the CPTu data stream without the need for any stoppage.
Abstract
This work develops a numerical technique in which the Particle Finite Element method is applied to simulate solid intrusion problems in Geotechnical Engineering. The work [...]
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Optimization of the heating system by electrical resistances in a rapid thermal response mold based on MSR-PSO-FEM
F. Cervantes Vallejo, K. Gómez, G. Soto, C. Navarro, H. Mendoza

Rev. int. métodos numér. cálc. diseño ing. (2019). Vol. 35, (3), 40

Abstract
The aim of this work to optimization of the heating system by electrical resistances for a rapid thermal response mold (MRTR), using the response surface methodology (MSR). Applying the design technique of the Box-Behnken experiments, a matrix of experiments with four factors and three levels was designed. The design variables that are used to describe the design and shape of the heating system are the heat flux per unit area of the electrical resistance, the distances from the center of the heaters to the surface of the cavity, the distance between the adjacent electrical resistors and the thickness of the heating plate. The heating time, the variation of the temperature in the cavity and the Von-Mises stress were considered as the variables of the model. Thermal and thermal-structural resistance analyzes of the model based on finite element method (FEM) are performed to acquire the objective variables. Mathematical response surface models are developed using the mixed regression model and the response surface model and the variance analysis method (ANOVA) is used to verify the accuracy of these mathematical models. With the obtained models, the position of the electric resistances is optimized and the ratio between mass and volume of the cavity insert is reduced to minimize the heating time within a reasonable temperature distribution and structural strength, coupling the surface models of response developed with the method of particle swarm optimization (PSO). The results obtained indicate that the required heating time on the surface of the cavity can be significantly reduced in the molding cycle, demonstrating with these the effectiveness of the heating system.
Abstract
The aim of this work to optimization of the heating system by electrical resistances for a rapid thermal response mold (MRTR), using the response surface methodology (MSR). [...]
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METODOLOGÍAS PARA EL DESARROLLO DE PROYECTOS DE MINERÍA DE DATOS
M. Botero Villada

Mario Botero Villada's personal collection (2019). 1

Abstract
A medida que la humanidad ha desarrollado y generado nuevo conocimiento a partir de investigaciones y estudios en diferentes áreas de la ciencia, se han acumulado grandes volúmenes de datos, hasta tal punto que obtener nueva información de estos se ha vuelto una tarea muy compleja en el que los análisis estadísticos demandan demasiado tiempo y dinero para ser ejecutados de forma manual. Aquí es donde entran las ciencias de la computación, específicamente la minería de datos para facilitar la forma en que estos volúmenes de datos pueden ser tratados. De esta forma, se explicará que es la minería de datos, los tipos de análisis, técnicas y sus principales metodologías para desarrollar proyectos de minería de datos en cualquier área de la ciencia.
Abstract
A medida que la humanidad ha desarrollado y generado nuevo conocimiento a partir de investigaciones y estudios en diferentes áreas de la ciencia, se han acumulado grandes [...]
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FACTORES ASOCIADOS AL DESARROLLO DE CANCÉR DE SENO
P. Botero Mejía

Paola Botero Mejía's personal collection (2019). 1

Abstract
El cáncer es una patología crónica no trasmisible, con incremento significativo en la incidencia y mortalidad a nivel mundial, incluyendo Latino América, Colombia y con una curva superior a la nacional el departamento de Caldas, Colombia. Se considera una patología de etiología multifactorial, que en los estudios han demostrado relaciones inversas o sin significancia epidemiológica, dentro de los factores asociados se encuentran la etnia, nivel socioeconómico y educativo, alimentación, actividad física, menarca, paridad, periodo de lactancia ofrecido a los hijos, exposiciones a ciertos virus, antecedentes familiares, red de apoyo, percepción individual y colectiva de calidad de vida, entre otros, que se detallan en el presente documento, buscando estructurar una estrategia que identifique población de alto riesgo para el desarrollo de cáncer de seno y permita realizar una tamización y diagnóstico oportuno desde la atención comunitaria.
Abstract
El cáncer es una patología crónica no trasmisible, con incremento significativo en la incidencia y mortalidad a nivel mundial, incluyendo Latino América, [...]
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AUTISTA SPECTRUM DISORDER: SEQUENCING AND CHANGES IN GENE EXPRESSION
Y. López E

Yéssica López E's personal collection (2019). 1

Abstract
Autism is a neurodevelopmental disorder characterized by commitment to social interaction and communication, associated with restricted interests and stereotyped behaviors. The genetic evidence of neurodevelopmental disorders is widely supported in the medical literature. The most recent protocols in the biomedical section of the genetic study of these disorders place the chromosomal microarrays and the exome sequencing as first-line analysis. As a result of the present review, the main sequencing methods used in the investigation and diagnosis of autistic spectrum disorder were identified, as were differential genetic expressions.
Abstract
Autism is a neurodevelopmental disorder characterized by commitment to social interaction and communication, associated with restricted interests and stereotyped behaviors. [...]
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Caffeine and sleep: Molecular and electrophysiological characteristics
L. Castaño Loaiza

Collection of Articles on Biochemistry, Genetics and Molecular Biology (2019). 2

Abstract
Caffeine is one of the most consumed stimulants in the world, being available in beverages such as coffee, chocolate, tea and energizers. It is a molecule used at the pharmacological level as an analgesic and causes psychostimulant effects related to decreased sleepiness, increased attention, modulation of memory and cognitive performance; In addition, it is recognized for the improvement of sports performance, among others (1). The relationship between sleep and caffeine has been widely investigated, it has been established that this methylxanthine can prolong sleep latency, generate less total sleep time with decreased deep sleep and a parallel increase in light sleep (2). Then, a review is presented that addresses the effect of caffeine on the polysomnographic stages of sleep and on the biological interactions that this substance presents in the adenosine receptors to which it joins; In addition, the genetic variations of these receptors will be taken into account, as possible causes of the changes induced by caffeine in sleep.
Abstract
Caffeine is one of the most consumed stimulants in the world, being available in beverages such as coffee, chocolate, tea and energizers. It is a molecule used at the pharmacological [...]
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Pharmacoepidemiology and bioinformatics: evolution and integration of analytical ways on precision therapeutics on cardiovascular risk
J. Pérez-Agudelo

Juan Manuel Pérez's personal collection (2019). 1

Abstract
The pharmacological intervention is positioned as a common element in the process of approaching patients at different levels of care, with the aim of limiting the natural evolution of various pathological conditions, generating symptomatic relief, preventing and in some circumstances, diagnosing. The use of therapeutic molecules within the framework of clinical decisions requires the conjunction and analysis of elements such as pharmacological, regulatory, epidemiological knowledge and individual characterization of the patient. This complex and multivariable scenario implies an important effort of the health professional, who will also find himself with a systematic element in front of the exposure to drugs: the adverse drug reactions, unwanted and within the therapeutic spectrum. To support the professional in the area of health sciences, bioinformatics and biostatistical information analysis processes arise, techniques that together with the advance in omics sciences, allow to describe, generate inference, explain, predict and apply knowledge of the science of data, at the bedside of the patient. The incorporation of bioinformatics and pharmacological analysis in complex levels of health care, with special reference to cardiovascular drugs, would allow to anticipate problems derived from interactions, indications, use, compliance and clinical impact.
Abstract
The pharmacological intervention is positioned as a common element in the process of approaching patients at different levels of care, with the aim of limiting the natural [...]
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Molecular mechanisms associated with azole resistance in Candida species
M. Rodríguez

Collection of Articles on Biochemistry, Genetics and Molecular Biology (2020). 1

Abstract
Opportunistic fungi of the Candida species have been associated with a broad spectrum of human infections with significant morbidity and mortality rates, ranging from superficial skin infections to deep or disseminated candidiasis. To combat this microorganism, antifungals are used, substances capable of specifically attacking fungi. Among them, the most commonly used are azoles, molecules characterized by an azole ring with various substituents, however, there has been widespread resistance to this type of antifungal agents. The objective of this review is to describe the main mechanisms of resistance to azole antifungals in fungal species of the genus Candida.
Abstract
Opportunistic fungi of the Candida species have been associated with a broad spectrum of human infections with significant morbidity and mortality rates, ranging from superficial [...]
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On the usage of augmented reality in hepatic oncosurgery
O. Palomares, E. Soudah, O. Coss, I. Valero, J. Pavía

Monograph CIMNE (2018). M183

Abstract
Half of all patients diagnosed with colorectal cancer develop liver metastasis during the course of their disease. Surgery provides the best opportunity for long-term survival and even the chance for cure. In order to achieve an adequate tumor resection, the surgeon must have precise knowledge of the tumor location relative to the surrounding major vascular structures. However, in order to do so, current surgeons have to continually look away from the patient to see the patient CT scan or MRI on a nearby monitor. Thus, there is then a clinical need for a better system that can assist surgeons. In this project, the feasibility of using augmented reality (AR) to assist open liver surgeries was studied. Separate volumes of liver surface, vascular and tumor structures were delineated from an animal's liver CT scan. These were then 3D printed and further rendered by means of a custom application within the HoloLens™ head-mounted display. The accuracy of image registration was subjectively evaluated by checking the alignment of the visible structures between the virtual model and the 3D printed model. By using a combination of tracked hand gestures and voice commands, the AR setup developed successfully indicated with high accuracy the location of the tumor and vasculature of the liver model. These significant results suggest that the superimposition of structures onto the patient liver could facilitate the orientation and navigation during a surgery. This would result in the improvement of tumor resection, leading to an increasing patient safety.
Abstract
Half of all patients diagnosed with colorectal cancer develop liver metastasis during the course of their disease. Surgery provides the best opportunity for long-term survival [...]
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Discrete Volume Method. A variational approach for brittle fracture
V. Cardoso, E. Oñate, S. Botello

Monograph CIMNE (2019). M184

Abstract
The Discrete Element Method has been used to simulate fracture dynamics beacuse its inherent capacity to reproduce multi-body interaction, but in the case of elasticity mechanics the microparameters of the numerical model, required to replicate the properties of the material, are difficult to calibrate. On the other hand, damage models based on finite element strategies can easily reproduce the properties of the media but they can not simulate the dynamics of multiple fractures. We propose a numerical approach, the Discrete Volume Method, to simulate fracture of brittle materials without the disadvantages mentioned, by combining the benefits of variational formulations and the numerical convenience of discrete element method to capture the dynamics of cracks. The Discrete Volume Method does not have microparameters, since the displacements are computed using the material properties and the fracture mechanism is controlled by an auxiliary damage field. Within this work we discuss a numerical strategy to solve the elasticity problem upon unstructured and non conforming meshes, allowing all kinds of flat-faced elements (polygons in 2D and polyhedra in 3D). The core of the formulation relies on two numerical procedures the Control Volume Function Approximation (CVFA), and the polynomial interpolation in the neighborhood of the control volumes, which is used to solve the surface integrals resulting from applying the divergence theorem. By comparing the estimated stress against the analytical stress field of the well known test of an infinite plate with a hole, we show that this conservative approach is robust and accurate. A similar strategy is used to get the damage field solution. In order to coupling both fields, displacement and damage, we use a finite increment arrangement for reducing the resdidual of elastic equation within each time step. We develop a numerical formulation for time discretization based on the analytical solution of the differential equation resulting from assuming a continuous variation of internal forces of the system between time steps. Finally, we show the effectiveness of the methodology by performing numerical experiments and comparing the solutions with published results.
Abstract
The Discrete Element Method has been used to simulate fracture dynamics beacuse its inherent capacity to reproduce multi-body interaction, but in the case of elasticity mechanics [...]
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Finite volume for stress analysis upon polygonal, unstructured and non conforming meshes
V. Cardoso Nungaray, S. Botello, F. Zarate, E. Oñate

Rev. int. métodos numér. cálc. diseño ing. (2019). Vol. 35, (4), 47

Abstract
Within this paper we discuss a numerical strategy to solve the elasticity problem upon unstructured and non conforming meshes, allowing all kinds of flat-faced elements (polygons in 2D and polyhedra in 3D). The core of the formulation relies on two numerical procedures 1) the Control Volume Function Approximation (CVFA), and 2) the polynomial interpolation in the neighborhood of the control volumes, which is used to solve the surface integrals resulting from applying the divergence theorem. By comparing the estimated stress against the analytical stress field of the well known test of an infinite plate with a hole, we show that this conservative approach is robust and accurate.
Abstract
Within this paper we discuss a numerical strategy to solve the elasticity problem upon unstructured and non conforming meshes, allowing all kinds of flat-faced elements (polygons [...]
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A modified Taylor Galerkin scheme for turbulent compressible flow simulation.
H. Burbridge, A. Scarabino, A. Awruch

Rev. int. métodos numér. cálc. diseño ing. (2019). Vol. 35, (3), 43

Abstract
As already demonstrated by different authors, the Taylor-Galerkin (TG) scheme, in the context of the Finite Element Method (FEM), is particularly suitable for the solution of supersonic flows. The TG scheme, using hexahedral finite elements with analytical evaluation of element matrices, is applied in this work. Tools to avoid locking and a shock capturing technique for the solution of supersonic viscous and non-viscous compressible flows are also employed. However, TG scheme usually presents instabilities in subsonic flows. Even in cases in which the free stream Mach number corresponds to supersonic flows, there are always flow regions, specifically near the walls of the immersed obstacles, where the speed is lower and the local Mach number corresponds to a subsonic flow. The Characteristic Based Split (CBS) scheme was developed in order to obtain a single method to improve the behavior with respect to TG method in subsonic and supersonic regimes. In the last two decades some works have shown advantages in convergence rates of the CBS method when compared to the TG algorithm. However, simulation time increases in the CBS method since split operations, typical of this algorithm, imply in additional element loops. In this paper a hybrid algorithm called Modified-Taylor-Galerkin scheme (MTG) is proposed. This algorithm presents advantages with respect to TG and CBS schemes in terms of convergence properties and computational processing time. In order to get an efficient algorithm, the element matrices are analytically integrated. This is performed with two different approaches. In the first approach the inverse matrix and the determinant of the Jacobian matrix at element level are evaluated with a reduced integration form, using the point located in the center of the element for mass, convective, diffusive and stabilization element matrices; all these matrices are integrated analytically. In the second approach, mass and convective matrices are calculated by a complete integration scheme (including the inverse matrix and the determinant of the Jacobian matrix at element level in the analytical expression to be integrated) and the diffusive and stabilization matrices are calculated with a reduced integration form, using the point located at the center of the element to calculate the inverse matrix and the determinant of the Jacobian matrix at element level. Finally, this work incorporates the Spalart-Allmaras (S-A) turbulence model using a conservative version of the transport equation, as proposed by the authors of the original S-A model in a later paper. Algorithms are tested to determine convergence rate improvements in both laminar and turbulent cases and for different Mach numbers (supersonic, transonic and subsonic flows).
Abstract
As already demonstrated by different authors, the Taylor-Galerkin (TG) scheme, in the context of the Finite Element Method (FEM), is particularly suitable for the solution [...]
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Computational Analysis Tools
J. García-Espinosa

Open Access Repository of the FIBRESHIP project (2019). 4

Abstract
This presentation was made at the Fibreship dissemination event hold at the Barcelona School of Nautical Studies (21st May 2019, Barcelona). It shows the advances made in the project regarding the development of different analysis tools to support design and inspection of large length FRP based ships.
Abstract
This presentation was made at the Fibreship dissemination event hold at the Barcelona School of Nautical Studies (21st May 2019, Barcelona). It shows the advances made [...]
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Fatigue Simulation of a fibre-glass ship
Presentations on Computational Methods in Naval Architecture and Offshore Engineering (2019). 5

Abstract
The use of composite materials to build marine structures is a fact. Prove of it is the construction of offshore turbines, military vessels, composite risers, etc. However, the characterization of such structures under fatigue loads is not well understood, what implies a larger scantling and safety ratios of the structures. Hence, it is necessary to develop numerical tools in order to predict this failure mode. The purpose of this work is to propose a numerical model for the analysis of the fatigue behaviour of marine structures made of composite laminates, which can be used to understand their behaviour in order to optimize them. The formulation proposed to simulate the fatigue phenomena is based on the Serial/Parallel Rule of Mixtures (S/P RoM) and a fatigue damage model previously developed for metals. The SPRoM can be understood as a constitutive law manager that provides the elastic and non-linear response of the composite from the constitutive performance of its constituent materials. The fatigue damage model is based on the definition of a reduction function which takes into account the cyclic degradation of the materials, acting on strength and stiffness; this function accounts for the number of cycles, maximum stress and stress amplitude. These two formulations are coupled applying the fatigue damage model to both composite components, fibre and matrix. Current work uses the numerical procedure developed to characterize fatigue in composites. The model is calibrated based on the assumption that the failure mechanism of longitudinal loaded UD laminates is fibre-driven, while the failure mechanism of transverse loaded UD laminates is matrix-driven. The composite resulting from this calibration is used, afterwards, to predict the fatigue performance laminated composites with different stacking sequences. The structure chosen for this analysis is a substructure of a fibreglass vessel. This work is in the scope of FibreShip Project H2020.
Abstract
The use of composite materials to build marine structures is a fact. Prove of it is the construction of offshore turbines, military vessels, composite risers, etc. However, [...]
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Procedure to Calibrate Composite Materials by Serial/Parallel Mixing Theory
J. Jurado Granados

Presentations on Computational Methods in Naval Architecture and Offshore Engineering (2019). 6

Abstract
The use of composite materials in the naval industry is a fact. Prove of it is composite materials are widely used in the marine industry (e.g. competition vessels and leisure boats), offshore industry and renewable energy industry. If engineers want to design reliable structures made of composites, the numerical tools have to be capable of accurately representing the behaviour of these materials, such as their high anisotropy and non-linear performance. Hence, a good model capable of taking into account the different failure modes of the laminates is required in order to reduce the uncertainty associated with the simulation of composite structures. There are many models capable of simulating the elastic and specific non-linear behaviour of laminates, while also accounting for their anisotropic behaviour. However, few of them are capable to take into account most of the composites failure modes in a general way. This work proposes using one of them, the Serial/Parallel Mixing Theory (SP RoM) [1]. The main advantage of the SP RoM versus other formulations is that the composite performance is obtained from the mechanical properties of its constituent materials. Therefore, once these are calibrated, different composite configurations can be analysed without further calibrations. The Serial/Parallel Mixing Theory (S/P RoM) acts as a constitutive law manager of the constituent materials, being capable of reproducing the composite performance in its linear and non-linear regime. In order to obtain the material parameters required by the formulation, this work proposes a set of different tests to obtain different loading conditions and failure modes. Then, a guideline to get the material parameters from the tests is given. Finally, the numerical results are compared with results obtained from an experimental campaign. These results show that, once all the material parameters are obtained for fibre and matrix, the formulation introduced is capable of representing all the failure modes of the composite for different loading conditions, as well as their failure strength. This work is in the scope of FibreShip Project H2020 [2]. REFERENCES [1] F. Rastellni, S. Oller, O. Salomon, E. Oñate Composite materials non-linear modelling for long fibre reinforced laminates: continuum basis, computational aspects and validations, Computers & Structures, 86 (9) (2008), pp. 879–896 [2] European Union’s Horizon 2020 research and innovation programme under grant agreement nº 723360 “Engineering, production and life-cycle management for the complete construction of large-length FIBRE-based SHIPs”. http://www.fibreship.eu/about
Abstract
The use of composite materials in the naval industry is a fact. Prove of it is composite materials are widely used in the marine industry (e.g. competition vessels and leisure [...]
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The CIMNE model for generating knowledge on computational engineering and its transfer to society
E. Oñate

(2017). Research Report, Nº PI417
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Nothing
Victor Cardoso Nungaray's personal collection (2019). 1
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CAPITULO 4 ELABORACIÓN DE MATERIALES DIDÁCTICOS PARA LA EDUCACIÓN Y TRANSFORMACIÓN SOCIAL EN NIÑOS, NIÑAS, ADOLESCENTES Y JÓVENES (NNAJ) DESDE LA ENSEÑANZAAPRENDIZAJE DE LA QUIMICA .
F. López, A. Bolaño, W. Gutiérrez, E. EIDEC

Monographs (2019). 1

Abstract
The book chapter is a contribution to education and is based on the development of didactic materials for the social transformation of children, youth and adolescents (NNJA) from the teaching-learning of Chemistry. Thus, they were taught to prepare materials, prepare organic fertilizers, and implement hydroponic crops with a view to solving real problems in everyday life from the teaching-learning of Chemistry, made with apprentices of the Atlantic Regional Seine. Practical work was carried out in the elaboration of organic fertilizers with a view to strengthening the culture on care and conservation of the environment, in which they are immersed. Likewise, a socio-demographic diagnostic assessment is made where it is detected that these children, youth and adolescents live in vulnerable sectors, with low economic resources from their family income and a medium level of malnutrition. An educational project of social transformation is implemented in this vulnerable population that have been trained with transmission processes in schools, affecting in large part the social growth of these families. In conclusion, a creative and dynamic pedagogical work was observed by the apprentices of the Technical Secondary Education offered by the SENA National Learning Service in the educational institutions of the department of Atlántico, taking as an example in the lower grades of the school environments, and it is clear that it is a didactic alternative that can be used in education through the teaching-learning processes of chemistry. PALABRA CLAVES: Educación, transformación social, materiales didácticos, enseñanzaaprendizaje, Química. KEYWORD: Education, social transformation, didactic materials, teaching-learning, Chemistry. 57 RETOS Y DESAFIOS Perspectivas de la Educación y La Empresa
Abstract
The book chapter is a contribution to education and is based on the development of didactic materials for the social transformation of children, youth and adolescents (NNJA) [...]
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CAPITULO 3 PROPUESTA DE OPTIMIZACIÓN DEL PROCESO PRODUCTIVO DEL CENTRO DE EMPLEO DE COMFENALCO SANTANDER SECCIONAL BUCARAMANGA, CON BASE EN LA RUTA DE EMPLEABILIDAD
J. Duarte, J. Gast, E. EIDEC

Monographs (2019). 2

Abstract
A partir de la inmersión de la institución Caja de Compensación Familiar Comfenalco Santander seccional Bucaramanga, donde mantienen una unidad de intermediación para el empleo se efectúa un análisis con el propósito de formular una propuesta que mejore el proceso que hace la institución entre solicitantes de empleo y las empresas que ofrecen vacantes. Para lograr este objetivo se realizó una encuesta a funcionarios encargados de cada uno de las etapas del procedimiento conocido internamente como ruta de empleabilidad, y con esta información se construyen estadísticas de eficacia de los procesos y se identifican oportunidades de mejora. Al final se entrega un perfil descriptivo y de indicadores de cómo estos procedimientos funcionan y se dan propuestas estratégicas que permitan mejorar dicha imagen. RETOS Y DESAFIOS Perspectivas de la Educación y La Empresa Colección de Investigación en Educación, Empresa y Sociedad - ISBN: 978-958-52030-1-3 Editorial EIDEC
Abstract
A partir de la inmersión de la institución Caja de Compensación Familiar Comfenalco Santander seccional Bucaramanga, donde mantienen una unidad de intermediación [...]
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LA INTELIGENCIA COLECTIVA EN LA EDUCACIÓN VIRTUAL Y A DISTANCIA
E. EIDEC

Monographs (2019). 3

Abstract
The present research work arises with the purpose of identifying the contributions of collective intelligence in Virtual and Distance Education, in students of the Minuto de Dios University Corporation. It presents a theoretical foundation based on post-development, critical pedagogy, cyberculture and collective intelligence. The study is qualitative descriptive and was carried out from the methodological strategy of the systematization of experiences, taking into account three guiding categories: challenges of the digital culture; support networks; significant experiences The results emphasize the autonomous, collaborative work and the configuration of virtual communities that recognize intercultural and intergenerational knowledge exchanges.
Abstract
The present research work arises with the purpose of identifying the contributions of collective intelligence in Virtual and Distance Education, in students of the Minuto [...]
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CAPITULO 1 ENTRE LA OFERTA Y LA DEMANDA: EL IDIOMA INGLÉS VISTO COMO UNA BARRERA INVISIBLE QUE INTERFIERE EN EL ACCESO A LA LABOR DOCENTE DE LAS PROFESIONALES EN EDUCACIÓN INICIAL
E. EIDEC

Monographs (2019). 4

Abstract
En el artículo que se presenta, se muestra cómo el inglés influye en diferentes campos disciplinarios. Por lo tanto, en el caso de la educación, este lenguaje ha llegado a penetrar en varios niveles de educación formal e informal; La educación superior, así como los maestros y futuros maestros, ya que muchos de los nuevos profesionales de la educación deben adaptar el inglés a sus discursos pedagógicos y sus prácticas. Este estudio, en el que se basó este artículo, utiliza un diseño cualitativo y un enfoque hermenéutico. Sin embargo, a pesar de tener una perspectiva intersubjetiva, se implementaron técnicas de recolección de datos cuantitativos y cuantitativos: talleres individuales, entrevistas semiestructuradas, grupos de discusión, observaciones no participantes y encuestas. Además, La investigación de la cual se derivó la redacción de este artículo se denominó Formación pedagógica de profesionales en educación infantil temprana y su relación con la didáctica en un contexto internacional, en el que participaron: Universidad Católica Luis Amigó de Medellín, Universidad del Maule de Chile y La Red. Iberoamericana de Pedagogía. Entre los hallazgos más significativos, se percibe cómo los profesionales no reciben suficiente capacitación en métodos de enseñanza de inglés, así como la incapacidad de obtener un trabajo debido al bajo dominio lingüístico del idioma inglés.
Abstract
En el artículo que se presenta, se muestra cómo el inglés influye en diferentes campos disciplinarios. Por lo tanto, en el caso de la educación, [...]
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FINANZAS CREATIVAS Y NOCIONES EN CIUDADANÍA - EDUCACIÓN FINANCIERA
E. EIDEC

Monographs (2019). 5

Abstract
En la actual sociedad moderna y mediada por el uso de las tecnologías, contar con los conocimiento financieros se convierte en una necesidad, ya que a diario el ser humano se enfrenta a la toma de decisiones importantes para el desarrollo de su propio bienestar, tales como: ¿qué producto comprar?, ¿cuál se consideraría más seguro y rentable?, en ¿dónde depositar los ahorros?, ¿qué y cuál préstamo es el que ofrece un costo más estable en el tiempo? … estas y otras razones son elementos necesarios para el fortalecimiento de las decisiones responsables y el desarrollo de la libertad personal, aspectos asociados a los rendimientos, costos y riesgos a la hora de elegir sobre ¿qué y cómo invertir?, tomando entonces, cada vez más relevancia en la necesidad de formarse en conocimientos financieros (Domínguez, 2013).
Abstract
En la actual sociedad moderna y mediada por el uso de las tecnologías, contar con los conocimiento financieros se convierte en una necesidad, ya que a diario el ser [...]
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EL LENGUAJE DE LAS REDES: TEJIDO DE SABERES EN EL TRABAJO PSICOSOCIAL CON FAMILIAS
E. EIDEC

Monographs (2019). 6

Abstract
El presente libro enfatiza en la promoción de las acciones coordinadas entre la familia, la escuela, la organización y las instituciones para generar una red protectora a favor de todos los ciclos vitales y grupos humanos. Este reto implica construir un sistema de corresponsabilidad basado en los recursos y las capacidades. Desde esta perspectiva de capacidades, se aprende a acompañar de manera colaborativa los intercambios de saberes.
Abstract
El presente libro enfatiza en la promoción de las acciones coordinadas entre la familia, la escuela, la organización y las instituciones para generar una red [...]
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RETOS Y DESAFÍOS PERSPECTIVAS DE LA EDUCACIÓN Y LA EMPRESA
E. EIDEC

Monographs (2019). 7

Abstract
Retos y desafíos perspectivas de la educación y la empresa son los temas centrales del volumen 1 de la colección: investigación en educación, empresa y sociedad, inherentes a procesos investigativos y reflexivos. Algunos capítulos abordan reflexiones y experiencias en materia de formación, tanto en investigación como en otros campos y prácticas del saber y el conocimiento. Algunos más analizan tópicos relacionados con la investigación y los procesos de apropiación, generación y uso del conocimiento. Y otros más orbitan sobre experiencias y procesos didácticos y metodológicos con el recurso tecnológico y de otros dispositivos, para fortalecer los aprendizajes en dominios dados del saber.
Abstract
Retos y desafíos perspectivas de la educación y la empresa son los temas centrales del volumen 1 de la colección: investigación en educación, [...]
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Estudio de estimación de parámetros constitutivos en el método de elementos discretos o de partículas
C. Recarey, E. Oñate, J. Miquel, F. Zárate, J. Rojek, S. Burrell

Monograph CIMNE (2005). M93

Abstract
Se presenta un modelo numérico que emplea elementos discretos esféricos o también denominados elementos distintos. Este modelo se aplica en la simulación de rocas, suelos, medios granulares y otros materiales. El movimiento de elementos esféricos se describe por medio de las ecuaciones de dinámica del cuerpo rígido. Se emplea en la formulación una integración explícita, la cual, brinda una buena eficiencia computacional.
Abstract
Se presenta un modelo numérico que emplea elementos discretos esféricos o también denominados elementos distintos. Este modelo se aplica en la simulación [...]
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Numerical simulation of multifluid flows with the particle finite element method
M. Mier, S. Idelsohn, E. Oñate

Monograph CIMNE (2010). M115

Abstract
In this monograph we have focused on understanding the basic physical principles of multi-fluid flows and the difficulties that arise in their numerical simulation. We have extended the Particle Finite Element Method to problems involving several different fluids with the aim of exploiting the fact that Lagrangian methods are specially well suited for tracking any kind of interfaces. We have developed a numerical scheme able to deal with large jumps in the physical properties (density and viscosity), include surface tension, and accurately represent all types of discontinuities in the flow variables at the interface. The scheme is based on decoupling the nodes position, velocity and pressure variables through the Picard linearization and a pressure segregation method which takes into account the interface conditions. The interface has been defined to be aligned with the moving mesh, so that it remains sharp along time. Furthermore, pressure degrees of freedom have been duplicated at the interface nodes to represent the discontinuity of this variable due to surface tension and variable viscosity, and the mesh has been refined in the vicinity of the interface to improve the accuracy of the computations.
Abstract
In this monograph we have focused on understanding the basic physical principles of multi-fluid flows and the difficulties that arise in their numerical simulation. We have [...]
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Computational model of the human urinary bladder
V. Monteiro, E. Oñate, S. Oller

Monograph CIMNE (2014). M148

Abstract
The proposal of an artificial bladder is still a challenge to overcome. Bladder cancer is among the most frequent cases of oncologic diseases in United States and Europe. It is considered a major medical problem once this disease has high rates of reoccurrence, often leading to the extirpation of this organ. The most refined solution to replace this organ is the ileal bladder, which consists of a neobladder made of the patient’s intestinal tissue. Unfortunately this solution presents not only functional mechanical problems, described on the literature as voiding and leaking problems, but also biological ones (i.e. bone loss, given the absorption by the intestine of substances that should be eliminated from the organism). Urged by the urological community of the Hospital Clinic de Barcelona and backgrounded by its experience in the numerical simulation of biomedical structures, the Center of Numerical Methods in Engineering (CIMNE) had the initiative to provide the research of the mechanics of the urinary bladder and the simulation of fluid structure interaction (FSI) to account for the filling and voiding of this organ with urine. The Finite Element Method (FEM) simulation of the real bladder and the comprehensive understanding of the mechanics of this organ and its interaction with urine will give the possibility to propose geometrical improvements and study suitable materials for an artificial solution to address the cases on which the bladder needs to be removed. To reach this goal, first we proceeded to the bibliographic review of mathematical models of the urinary apparatus and to a comprehensive study of the physiology and dynamics of the bladder. A review of the major urological structures, kidney, ureter and urethra, takes place. To consider boundary conditions other surrounding structures to the urinary system are also studied. In the second part of the thesis, we propose the numerical model to study the human urinary bladder. The behavior of the detrusor muscle during filling and voiding of the bladder with urine and its ability to promote the storage of urine under low pressure need to be accurately represented, requiring the implementation of a non-linear constitutive model. The mathematical model needs to be capable to simulate the mechanical variables that govern this organ and the properties of the urine. The nonlinear behavior of living tissues is implemented and validated with examples from the literature. The quasi-incompressibility property of urine and the navierstokes equations for the fluid are taken into account. The geometry of the bladder needs to be taken into account, and the implementation of a 3D computational model obtained from the computerized tomography of a cadaver male adult is considered. The data has been treated to consider boundary conditions. Two models have been conceived: one meshed with four nodes tetrahedral and another meshed with shell elements. FSI must work for the simulation of filling and voiding of the bladder. Due to the close densities of the materials the scheme used to solve fluid-structure needs to be carefully selected. The proposed numerical model and the filling and voiding analysis are finally validated with standardized urodynamic tests. The final part of the thesis, the simulation of a neobladder is presented, being the first step to simulate numerically artificial materials for bladder replacement.
Abstract
The proposal of an artificial bladder is still a challenge to overcome. Bladder cancer is among the most frequent cases of oncologic diseases in United States and Europe. [...]
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Development and applications of the finite point method to compressible aerodynamics problems
E. Ortega, E. Oñate, S. Idelsohn

Monograph CIMNE (2014). M143

Abstract
This work deals with the development and application of the Finite Point Method (FPM) to compressible aerodynamics problems. The research focuses mainly on investigating the capabilities of the meshless technique to address practical problems, one of the most outstanding issues in meshless methods. The FPM spatial approximation is studied firstly, with emphasis on aspects of the methodology that can be improved to increase its robustness and accuracy. Suitable ranges for setting the relevant approximation parameters and the performance likely to be attained in practice are determined. An automatic procedure to adjust the approximation parameters is also proposed to simplify the application of the method, reducing problem- and user-dependence without affecting the flexibility of the meshless technique. The discretization of the flow equations is carried out following wellestablished approaches, but drawing on the meshless character of the methodology. In order to meet the requirements of practical applications, the procedures are designed and implemented placing emphasis on robustness and efficiency (a simplification of the basic FPM technique is proposed to this end). The flow solver is based on an upwind spatial discretization of the convective fluxes (using the approximate Riemann solver of Roe) and an explicit time integration scheme. Two additional artificial diffusion schemes are also proposed to suit those cases of study in which computational cost is a major concern. The performance of the flow solver is evaluated in order to determine the potential of the meshless approach. The accuracy, computational cost and parallel scalability of the method are studied in comparison with a conventional FEM-based technique. Finally, practical applications and extensions of the flow solution scheme are presented. The examples provided are intended not only to show the capabilities of the FPM, but also to exploit meshless advantages. Automatic hadaptive procedures, moving domain and fluid-structure interaction problems, as well as a preliminary approach to solve high-Reynolds viscous flows, are a sample of the topics explored. All in all, the results obtained are satisfactorily accurate and competitive in terms of computational cost (if compared with a similar mesh-based implementation). This indicates that meshless advantages can be exploited with efficiency and constitutes a good starting point towards more challenging applications.
Abstract
This work deals with the development and application of the Finite Point Method (FPM) to compressible aerodynamics problems. The research focuses mainly on investigating [...]
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A general stabilized formulation for incompressible fluid flow using finite calculus and the finite element method
E. Oñate, J. García, G. Bugeda, S. Idelsohn

(2003). Fluid Dynamics and Aeronautics New Challenges, Périaux J., Champion M., Gagnepain J.-J., Pironneau O., Stoufflet B. and Thomas Ph.(Eds.), CIMNE, Barcelona, Spain

Abstract
We present a general formulation for incompressible fluid flow analysis using the finite element method (FEM). The necessary stabilization for dealing with convective effects and the incompressibility condition are introduced via the so called finite calculus (FIC) method. The extension of the standard eulerian form of the equations to an arbitrary lagrangian-eulerian (ALE) frame adequate for treating fluid-structure interaction problems is presented. The fully lagrangian form is also discussed. Details of an effective mesh updating procedure are presented together with a method for dealing with free surface effects of importance for ship hydrodynamic analysis and many other fluid flow problems. Examples of application of the eulerian, the ALE and the fully lagrangian flow descriptions are presented.
Abstract
We present a general formulation for incompressible fluid flow analysis using the finite element method (FEM). The necessary stabilization for dealing with convective effects [...]
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Lagrangian formulation for fluid-structure interaction problems using the particle finite element method
E. Oñate, S. Idelsohn, M. Celigueta

(2006). Verification and Validation Methods for Challenging Multiphysics Problems, CIMNE, pp. 125-150

Abstract
We present a general formulation for analysis of fluid-structure interaction problems using the particle finite element method (PFEM). The key feature of the PFEM is the use of an updated Lagrangian description to model the motion of nodes (particles) in both the fluid and the structure domains. Nodes are viewed as material points (called particles) particles which can freely move and even separate from the main analysis domain representing, for instance, the effect of water drops. A mesh connects the nodes defining the discretized domain where the governing equations, expressed in an integral from, are solved as in the standard FEM. The necessary stabilization for dealing with the incompressibility of the fluid is introduced via the finite calculus (FIC) method. An incremental iterative scheme for the solution of the non linear transient coupled fluid-structure problem is described. Examples of application of the PFEM to solve a number of fluid-structure interaction problems involving large motions of the free surface and splashing of waves are presented.
Abstract
We present a general formulation for analysis of fluid-structure interaction problems using the particle finite element method (PFEM). The key feature of the PFEM is the use [...]
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Residual stress and distortion of rectangular and S-shaped Ti-6Al-4V parts by Directed Energy Deposition: Modelling and experimental calibration
X. Lu, X. Lin, M. Chiumenti, M. Cervera, Y. Hu, X. Ji, L. Ma, H. Yang, W. Huang

Additive Manufacturing (2019). (preprint) Vol. 26, pp. 166-179

Abstract
Residual stresses and distortion in Additive Manufactured (AM) parts are two key obstacles which seriously hinder the wide application of this technology. Nowadays, understanding the thermomechanical behavior induced by the AM process is still a complex task which must take into account the effects of both the process and the material parameters, the microstructure evolution as well as the pre-heating strategy. One of the challenges of this work is to increase the complexity of the geometries used to study the thermomechanical behavior induced by the AM process. The reference geometries are a rectangular and a S-shaped structures made of 44-layers each. The samples have been fabricated by Directed Energy Deposition (DED). In-situ thermal and distortion histories of the substrate are measured in order to calibrate the 3D coupled thermo-mechanical model. Once the numerical results showed a good agreement with the temperature measurements, the validated model has been used to predict the residual stresses and distortions. Different process parameters have been analyzed to study their sensitivity to the process assessment. Different preheating strategies have been also analyzed to check their effectiveness on the mitigation of both distortions and residual stresses. Finally, some simplifications of the actual scanning sequence are proposed to reduce the computational cost without loss of the accuracy of the simulation framework.
Abstract
Residual stresses and distortion in Additive Manufactured (AM) parts are two key obstacles which seriously hinder the wide application of this technology. Nowadays, understanding [...]
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In situ measurements and thermo-mechanical simulation of Ti–6Al–4V laser solid forming processes
X. Lu, X. Lin, M. Chiumenti, M. Cervera, Y. Hu, X. Ji, L. Ma, W. Huang

Int. J. Mechanical Sciences (2019). (preprint) Vol. 153-154, pp. 119-130

Abstract
Residual stresses and distortions are two technical obstacles for popularizing the additive manufacturing (AM) technology. The evolution of the stresses in AM components during the thermal cycles of the metal depositing process is not yet clear, and more accurate in situ measurements are necessary to calibrate and validate the numerical tools developed for its simulation. In this work a fully coupled thermo-mechanical analysis to simulate the laser solid forming (LSF) process is carried out. At the same time, an exhaustive experimental campaign is launched to measure the temperature evolution at different locations, as well as the distortions and both the stress and strain fields. The thermal and mechanical responses of single-wall coupons under different process parameters are recorded and compared with the numerical models. Good agreement between the numerical results and the experimental measurements is obtained. Sensitivity analysis demonstrates that the AM process is significantly affected by the laser power and the feeding rate, while poorly influenced by the scanning speed.
Abstract
Residual stresses and distortions are two technical obstacles for popularizing the additive manufacturing (AM) technology. The evolution of the stresses in AM components during [...]
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Out-of-plane seismic response and failure mechanism of masonry structures using finite elements with enhanced strain accuracy
G. Vlachakis, M. Cervera, G. Barbat, S. Salaustros

Engineering Failure Analysis (2019). (preprint) Vol. 97, pp. 534-555

Abstract
The out-of-plane response is a complex and at the same time key aspect of the seismic vulnerability of masonry structures. It depends on several factors, some of which are the material properties, the quality of the walls, the geometry of the structure, the connections between structural elements and the stiffness of the diaphragms. During the last years, a wide variety of numerical methods has been employed to assess the out-ofplane behaviour of unreinforced masonry structures. Finite element macro-modelling approaches are among the most famous as they allow modelling large structures at a reasonable computational cost. However, macro-modelling approaches may result in a non-realistic representation of localized cracks and a dependency of the numerical solution on the finite element mesh. Mixed strain/displacement finite elements have been recently proposed as a remedy to the above numerical pathologies. Due to the independent interpolation of strains and displacements these finite element formulations are characterized by an enhanced accuracy in strain localization and crack propagation problems, being at the same time practically mesh independent. For these reasons, mixed finite elements are employed in this work for the out-of-plane assessment of unreinforced masonry structures, being at the same time their first real-scale application. A full-scale experimental campaign of two masonry structures, a stone and a brick one, subjected to shaking-table tests is chosen as reference benchmark. Their structural response under seismic actions is numerically assessed through nonlinear static analysis. The proposed approach is validated through the comparison of the numerical results with the experimental ones, as well as with the results obtained using standard irreducible finite elements.
Abstract
The out-of-plane response is a complex and at the same time key aspect of the seismic vulnerability of masonry structures. It depends on several factors, some of which are [...]
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Effect of the tool tilt angle on the material flow and heat generation in Friction Stir Welding
N. Dialami, M. Cervera, M. Chiumenti

Metals (2019). Vol. 9 (1), pp. 28-45

Abstract
This work studies the effect of the tool tilt angle on the generated heat and the material flow in the work pieces joint by Friction Stir Welding (FSW). An apropos kinematic framework together with a two-stage speed-up strategy is adopted to simulate the FSW problem. The effect of tilt angle on the FSWelds is modeled through the contact condition by modifying an enhanced friction model. A rotated friction shear stress is proposed, the angle of rotation depending on the process parameters and the tilt angle. The proposed rotation angle is calibrated by the experimental data provided for a tilt angle 2.5◦ . The differences of generated heat and material flow for the cases of tool with tilt angle of 0◦ and 2.5◦ are discussed. It is concluded that due to the higher temperature, softer material and greater frictional force in the trailing side of the tool, the material flow in the rear side of the FSW tool with the title angle is considerably enhanced, which assists to prevent the generation of defect.
Abstract
This work studies the effect of the tool tilt angle on the generated heat and the material flow in the work pieces joint by Friction Stir Welding (FSW). An apropos kinematic [...]
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Tool development for fully coupled simulation of offshore wind turbine
J. Gutiérrez Romero, B. Servan Camas, A. García, J. Colom Cobb, J. García-Espinosa

VIII International Conference on Computational Methods in Marine Engineering (Marine 2019), Gothenburg (Sweden)

Abstract
Nowadays the marine renewable energies are getting an important role in the transformation of the energy model. And tools for predicting the performance of these new technologies are essential in their commercial development. An example of these are floating wind turbines (FWT), and this work presents the coupling and verification of a set of tools to carry out fully coupled simulation of FWTs. These tools are built on the seakeeping software SeaFEM [1, 2, 3, 4, 5] and on the aeroelastic simulator code FAST [6]. First, the basic features of each tools are explained. Second, a coupling strategy to assess the performance of FWTs is presented. Third, the results obtained coupling SeaFEM-FAST are used for an inter-code comparison against those obtained coupling Hydrodyn-FAST. Forth, an intensive analysis of a FWT based on the NREL 5 MW baseline is carried out taking into account the environmental conditions of the selected location. These coupled computations are carried out following the Design Load Cases proposed by IEC rules [7] to assess the Ultimate Limit State (ULS). Finally, some comparison and conclusions based on the obtained results are drawn.
Abstract
Nowadays the marine renewable energies are getting an important role in the transformation of the energy model. And tools for predicting the performance of these new technologies [...]
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Finite Element Analysis of Membrane Structures
R. Taylor, E. Oñate, P. Ubach de Fuentes

(2005). Recent Advances in Textile Membranes and Inflatable Structures, Springer Verlag, pp. 47 - 68

Abstract
This paper summarizes the development for a large displacement formulation of a membrance composed of three-node triangular elements. A formulation in terms of the deformation gradient is first constructed in terms of nodal variables. In particular, the use of the right Cauchy-Green deformation tensor is shown to lead to a particulary simple representation in terms of nodal quantities. This may then be used to construct general models for use in static and transient analyses.
Abstract
This paper summarizes the development for a large displacement formulation of a membrance composed of three-node triangular elements. A formulation in terms of the deformation [...]
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Thermo-mechanical analysis of laminated composites exposed to fire
D. Di Capua, J. García-Espinosa, R. Pacheco, O. Casals, T. Korhonen, T. Hakkarainen, A. Paajanen

VIII International Conference on Computational Methods in Marine Engineering (Marine 2019), Gothenburg (Sweden)

Abstract
This presentation introduces a numerical model for the thermo-mechanical analysis of laminated composite structures under the fire action. The coupling between the thermal and mechanical behaviour is considered in weak form (temperatures field modify mechanical properties but displacements field do not modify thermal properties). The thermal part of model is based on the approach presented in Henderson et al. (1985). This model takes into account the energy transfer processes of heat conduction, pyrolysis of the polymer matrix, and diffusion of decomposition gases. The mechanical behaviour of the composites is based on the serial/parallel mixing theory (Rastellini et al., 2008) which is modified to take into account the thermal degradation of the mechanical properties. Numerical results obtained with this model are compared with some experimental tests presented in the literature. Application of the developed model to the analysis of fire scenarios in composite ships is evaluated.
Abstract
This presentation introduces a numerical model for the thermo-mechanical analysis of laminated composite structures under the fire action. The coupling between the thermal [...]
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Advances in the simulation of ship navigation in ice
J. Colom Cobb, B. Servan Camas, J. García-Espinosa, E. Oñate

VIII International Conference on Computational Methods in Marine Engineering (Marine 2019), Gothenburg (Sweden)

Abstract
Navigation in the arctic regions is becoming more usual as new navigations routes are being opened due to the retreatment of the ice. This means that ships will be navigating in brash ice, which is the accumulation of floating ice made up of blocks no larger than two meters across, bringing up new concerns on the interaction of ice locks with the ship. In this work, we tackle these concerns and present the advances towards the development of a computational model for simulation of this navigation condition including the interaction among the ship and the ice blocks. The computational tool developed in this work is based on the coupling of a Semi-Lagrangian Particle Finite Element Method (SL-PFEM) with a multi rigid-body dynamics tool. The Particle Finite Element Method [1] is a versatile framework for the analysis of fluid-structure interaction problems. The PFEM combines Lagrangian particle-based techniques with the advantage of the integral formulation of the Finite Element Method (FEM). It has been shown [1][2] to successfully simulate a wide variety of complex engineering problems, e.g. free-surface/multi-fluid flows with violent interface motions, multi-fluid mixing and buoyancy-driven segregation problems etc. The latest development within the framework of the PFEM is the X-IVAS (eXplicit Integration along the Velocity and Acceleration Streamlines) scheme [2][3]. It is a semi-implicit scheme built over a Semi-Lagrangian (SL) formulation of the PFEM. In this work, the SL-PFEM model has been coupled with a multibody dynamics solver, able to handle the interactions between thousands of bodies, representing the different ice blocks. The interaction between the fluid flow and the ice blocks is taking into account by enriching the finite element space at the boundaries of the different blocks. This work is part of the research project NICESHIP sponsored by the U.S. Office of Naval Research under Grant N62909-16-1-2236.
Abstract
Navigation in the arctic regions is becoming more usual as new navigations routes are being opened due to the retreatment of the ice. This means that ships will be navigating [...]
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A second-order semi-Lagrangian particle FEM method for the incompressible NavierStokes equations
B. Serván-Camas, J. Colom-Cobb, J. García-Espinosa, P. Nadukhandi

VIII International Conference on Computational Methods in Marine Engineering (Marine 2019), Gothenburg (Sweden)

Abstract
In this work, a second-order semi-Lagrangian particle finite element method (SL-PFEM) is presented. The method is based on the second order velocity Verlet algorithm, using an explicit scheme to integrate the particles’ trajectories, and an implicit Crank-Nicholson scheme to integrate the particle’s velocities. The projection of the particle´s intrinsic variables onto the finite element (FE) mesh is based on a second-order global least-square. The elliptic part of the Navier-Stokes equations is discretized with the Crank-Nicholson scheme and solved using an iterative process. The method is verified against available analytical solutions, and applied to the classic flow around a cylinder problem.
Abstract
In this work, a second-order semi-Lagrangian particle finite element method (SL-PFEM) is presented. The method is based on the second order velocity Verlet algorithm, using [...]
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Stabilization via finite calculus in finite element computations
E. Oñate

(2004). Finite Element Methods: 1970's and Beyond, Franca L.P., Tezduyar T.E. and Masud A. (Eds.),CIMNE, Barcelona, Spain

Abstract
The expression “finite calculus” refers to the derivation of the governing differential equations in mechanics by invoking balance of fluxes, forces, etc. in a space-time domain of finite size. The governing equations resulting from this approach are different from those of infinitesimal calculus theory and they incorporate new terms which depend on the dimensions of the balance domain. The new governing equations allow to derive naturally stabilized numerical schemes using any discretization procedure. The paper discusses the possibilities of the finite calculus method for the finite element solution of convection-diffusion problems with sharp gradients and incompressible fluid flow.
Abstract
The expression “finite calculus” refers to the derivation of the governing differential equations in mechanics by invoking balance of fluxes, forces, etc. in a [...]
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FE Analysis of membrane systems including wrinkling and coupling
R. Rossi, R. Vitaliani, E. Oñate

(2005). Recent Advances in Textile Membranes and Inflatable Structures, Springer Verlag, pp. 89 - 108

Abstract
Current work summarizes the experience of the writer in the modeling of membrane systems. A first subsection describes an efficient membrane model, together with a reliable solution procedure. The following section addresses the simulation of the wrinkling phenomena providing details of a new solution procedure. The last one proposes an efficient technique to obtain the solution of the fluid structural interaction problem.
Abstract
Current work summarizes the experience of the writer in the modeling of membrane systems. A first subsection describes an efficient membrane model, together with a reliable [...]
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Enhanced Rotation-Free Basic Shell Triangle. Applications to Sheet Metal Forming
E. Oñate, F. Flores, L. Neamtu

(2007). Computational Plasticity, E. Oñate and R. Owen (Eds.), pp. 239-265

Abstract
An enhanced rotation-free three node triangular shell element (termed EBST) is presented. The element formulation is based on a quadratic interpolation of the geometry in terms of the six nodes of a patch of four triangles associated to each triangular element. This allows to compute an assumed constant curvature field and an assumed linear membrane strain field which improves the in-plane behaviour of the element. A simple and economic version of the element using a single integration point is presented. The implementation of the element into an explicit dynamic scheme is described. The efficiency and accuracy of the EBST element and the explicit dynamic scheme are demonstrated in many examples of application including the analysis of a cylindrical panel under impulse loading and sheet metal stamping problems.
Abstract
An enhanced rotation-free three node triangular shell element (termed EBST) is presented. The element formulation is based on a quadratic interpolation of the geometry in [...]
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A unified symmetrical formulation for interactions between elastic solids and incompressible fluids
S. Idelsohn, E. Oñate, J. Marti

(2007). Variational Formulations in Mechanics: Theory and Applications, E. Taroco, E.A. de Souza Neto and A.A. Novotny (Eds.), CIMNE, Barcelona, Spain

Abstract
We present a general Lagrangian formulation for treating elastic solids and quasi/fully incompressible fluids in a unified form. The formulation allows to treat solid and fluid subdomains in a unified manner in fluid-structure interaction (FSI) situations. The use for both fluid and solid of a Lagrangian formulation avoid convective terms allowing to approximate the problem via a Variational Formulation. In our work the FSI problem is solved via the Particle Finite Element Method (PFEM). The PFEM is an effective technique for modeling complex interactions between floating and submerged bodies and free surface flows, accounting for splashing of waves, large motions of the bodies and frictional contact conditions. Applications of the unified Lagrangian formulation to a number of FSI problems are given.
Abstract
We present a general Lagrangian formulation for treating elastic solids and quasi/fully incompressible fluids in a unified form. The formulation allows to treat solid and [...]
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Fluid-soil-structure interaction analysis with the particle finite element method
E. Oñate, M. Celigueta, S. Idelsohn, F. Salazar, B. Suarez

(2012). Bytes and Science, G. Zavarise and D. Boso (Eds.), pp. 119 - 130, CIMNE, Barcelona Spain

Abstract
We present some developments and applications of the Particle Finite Element Method (PFEM) for analysis of complex coupled problems in mechanics involving fluid-soil-structure interaction.
Abstract
We present some developments and applications of the Particle Finite Element Method (PFEM) for analysis of complex coupled problems in mechanics involving fluid-soil-structure [...]
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Experiences in the Design Analysis and Construction of Low Pressure Inflatable Structures
J. Marcipar, E. Oñate, J. Canet

(2005). Recent Advances in Textile Membranes and Inflatable Structures, Springer Verlag, pp. 241 - 257
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Applications of a Rotation-Free Triangular Element for Finite Strain Analysis of Thin Shells and Membranes
F. Flores, E. Oñate

(2005). Recent Advances in Textile Membranes and Inflatable Structures, Springer Verlag, pp. 69 - 88

Abstract
This paper shows applications of a recently developed shell element to the analysis of thin shell and membrane structures. The element is a three node triangle with only translational DOFs (rotation free) that uses the configuration of the three adjacent elements to evaluate the strains. This allows to compute (constant) bending strains and (linear) membrane strains. A total Lagrangian formulation is used. Strains are defined in terms of the principal stretches. This allows to consider rubber materials and other type of materials using the Hencky stress-strain pair. An explicit central difference scheme is used to integrate the momentum equations. Several examples, including inflation and deflation of membranes show the excellent convergence properties and robustness of the element for large strain analysis of thin shells and membranes.
Abstract
This paper shows applications of a recently developed shell element to the analysis of thin shell and membrane structures. The element is a three node triangle with only translational [...]
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Membrane Structures Formed by Low Pressure Inflatable tubes. New Analysis Methods and Recent Constructions
E. Oñate, F. Flores, J. Marcipar

(2008). Textile Composites and Inflatable Structures II, E. Oñate and B. Kröplin (eds.), pp. 163-196

Abstract
This paper shows applications of a recently developed thin shell element adequate for the analysis of membrane and inflatable structures. The element is a three node triangle with only translational degrees of freedom that uses the configuration of the three adjacent elements to evaluate the strains in terms of the nodal displacements only. This allows to compute (constant) bending strains and (linear) membrane strains using a total Lagrangian formulation. Several examples, including inflation and deflation of membranes and some practical applications to the analysis, design and construction of membrane structures formed by low pressure inflatable tubes are presented.
Abstract
This paper shows applications of a recently developed thin shell element adequate for the analysis of membrane and inflatable structures. The element is a three node triangle [...]
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Prediction of joint line remnant defect in friction stir welding
N. Dialami, M. Cervera, M. Chiumenti, A. Segatori

Int. J. Mechanical Sciences (2019). Vol. 151, pp. 61-69

Abstract
This work studies computationally and experimentally the joint line remnant defects emerging in friction stir welding (FSW) due to oxide layer propagation into the weld. A finite element-based model is used for the computational simulation. To follow the evolution of the oxide layer originally placed between the butted surfaces, a material tracing technique is incorporated in the numerical model. This approach allows tracking the position of the tracers representing oxide layer particles knowing the nodal velocities. A robust and fast two-stage numerical strategy is adopted for the analysis of FSW process to solve the underlying thermo-mechanical problem. The first stage is a speed-up stage solved on a fixed mesh that allows to quickly obtain the steady state. Oxide layer evolution is traced in the second stage where the rotation of the tool is modelled. Experimentally, to produce a clearly dispersed oxide line in the weld, one of the workpieces is anodized while the other one is taken as extruded. The computationally obtained oxide layer patterns are compared to those obtained experimentally using macrograph analysis of the joint cross section. The effect of the pin features and the process parameters on the final result is studied. The results show that with appropriate modelling of the material tracers in FSW, significant agreement can be attained between the computed and measured post-FSW oxide layer evolved results.
Abstract
This work studies computationally and experimentally the joint line remnant defects emerging in friction stir welding (FSW) due to oxide layer propagation into the weld. A [...]
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Challenges, tools and applications of tracking algorithms in the numerical modelling of cracks in concrete and masonry structures
S. Salaustros, M. Cervera, L. Pelà

Archives of Comp. Meths. Engng. (2018). (preprint) Published online, pp. 1-45

Abstract
The importance of crack propagation in the structural behaviour of concrete and masonry structures has led to the development of a wide range of finite element methods for crack simulation. A common standpoint in many of them is the use of tracking algorithms, which identify and designate the location of cracks within the analysed structure. In this way, the crack modelling techniques, smeared or discrete, are applied only to a restricted part of the discretized domain. This paper presents a review of finite element approaches to cracking focusing on the development and use of tracking algorithms. These are presented in four categories according to the information necessary for the definition and storage of the crack-path. In addition to that, the most utilised criteria for the selection of the crack propagation direction are summarized. The various algorithmic issues involved in the development of a tracking algorithm are discussed through the presentation of a local tracking algorithm based on the smeared crack approach. Challenges such as the modelling of arbitrary and multiple cracks propagating towards more than one direction, as well as multi-directional and intersecting cracking, are detailed. The presented numerical model is applied to the analysis of small- and large-scale masonry and concrete structures under monotonic and cyclic loading.
Abstract
The importance of crack propagation in the structural behaviour of concrete and masonry structures has led to the development of a wide range of finite element methods for [...]
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Modeling of microstructure evolution of Ti6Al4V for Additive Manufacturing
E. Salsi, M. Chiumenti, M. Cervera

Metals (2018). Vol. 8 (8), pp. 633-657

Abstract
AM processes are characterized by complex thermal cycles that have a deep influence on the microstructural transformations of the deposited alloy. In this work, a general model for the prediction of microstructure evolution during solid state transformations of Ti6Al4V is presented. Several formulations have been developed and employed for modeling phase transformations in other manufacturing processes and, particularly, in casting. The proposed model is mainly based on the combination and modification of some of these existing formulations, leading to a new overall model specifically dedicated to AM. The accuracy and suitability of the integrated model is enhanced, introducing new dedicated features. In fact the model is designed to deal with fast cooling and re-heating cycles typical of AM processes because: (a) it is able to consider incomplete transformations and varying initial content of phases and (b) it can take into account simultaneous transformations.The model is implemented in COMET, an in-house Finite Element (FE)-based framework for the solution of thermo-mechanical engineering problems. The validation of the microstructural model is performed by comparing the simulation results with the data available in the literature. The sensitivity of the model to the variation of material parameters is also discussed.
Abstract
AM processes are characterized by complex thermal cycles that have a deep influence on the microstructural transformations of the deposited alloy. In this work, a general [...]
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Numerical analysis of the manufacturing processes of a mock-up of the ITER NHF First Wall Panel
J. González, M. Chiumenti, M. Cervera, C. Agelet de Saracibar, F. Samaniego, I. Cobo

Fusion Engineering and Design (2018). (preprint) Vol. 135, Part A, pp. 65-73

Abstract
The objective of ITER is to build a new Tokamak, with the goal of demonstrating the scientific and technical feasibility of fusion power. The First Wall Panels are the inner component of the reactor, built with different materials that must support high heat flux levels inside the vacuum vessel. The manufacturing processes of the First Wall are a complex procedure including bending, hipping and cutting procedures which, in general, lead to residual stresses and distortions of the fabricated component. In this work, the analysis of the thermo-mechanical response of a simplified prototype of the ITER NHF First Wall Panel is presented from the numerical point of view. The experimental procedure within each phase of the whole manufacturing process is described. Residual stresses and distortions have been measured and analyzed. The numerical simulation of the manufacturing process includes the description of the main hypothesis, the applied loads and the boundary conditions assumed at every stage of the process. Special attention is paid to the simulation of machining and cutting by means of an ad-hoc element deactivation strategy. The numerical results are compared with the experimental evidence to show the prediction capability and the limitations of the proposed numerical model.
Abstract
The objective of ITER is to build a new Tokamak, with the goal of demonstrating the scientific and technical feasibility of fusion power. The First Wall Panels are the inner [...]
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Approximating the Basset force by optimizing the method of van Hinsberg et al.
G. Casas, A. Ferrer, E. Oñate

Journal of Computational Physics (2018). Vol. 352, pp. 142-171

Abstract
In this work we put the method proposed by van Hinsberg et al. to the test, highlighting its accuracy and efficiency in a sequence of benchmarks of increasing complexity. Furthermore, we explore the possibility of systematizing the way in which the method's free parameters are determined by generalizing the optimization problem that was considered originally. Finally, we provide a list of worked-out values, ready for implementation in large-scale particle-laden flow simulations.
Abstract
In this work we put the method proposed by van Hinsberg et al. to the test, highlighting its accuracy and efficiency in a sequence of benchmarks of increasing complexity. [...]
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Triangular prismatic solid-shell element with generalised deformation description
V. Mataix Ferrándiz, F. Flores, R. Rossi, E. Oñate

European Journal of Computational Mechanics (2018). Vol. 27 (1), pp. 1-32

Abstract
The solid-shells are an attractive kind of element for the simulation of f orming processes, due to the fact that any kind of generic 3D constitutive law can be employed without any kind of additional modification, besides the thermomechanic problem is formulated without additional assumptions. Additionally, this type of element allows the three-dimensional description of the deformable body, thus contact on both sides of the element can be treated easily. The present work consists in the development of a triangular prism element as a solid-shell, for the analysis of thin/thick shell, undergoing large deformations. The element is formulated in total Lagrangian formulation, and employs the neighbour (adjacent) elements to perform a local patch to enrich the displacement field. In the original formulation by Flores, a modified right Cauchy-Green deformation tensor () is obtained; in the present work a modified deformation gradient () is obtained, which allows to generalise the methodology and allows to employ a wide range of constitutive laws. The element is based in three modifications: (a) a classical assumed strain approach for transverse shear strains (b) an assumed strain approach for the in-plane components using information from neighbour elements and (c) an averaging of the volumetric strain over the element. The objective is to use this type of elements for the simulation of shells avoiding transverse shear locking, improving the membrane behaviour of the in-plane triangle and to handle quasi-incompressible materials or materials with isochoric plastic flow. Some examples have been evaluated to show the good performance of the element and results.
Abstract
The solid-shells are an attractive kind of element for the simulation of f orming processes, due to the fact that any kind of generic 3D constitutive law can be employed without [...]
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Finite element modelling of fracture propagation in saturated media using quasi-zero-thickness interface elements
I. de-Pouplana, E. Oñate

Computers and Geotechnics (2018). Vol. 96, pp. 103-117

Abstract
A new computational technique for the simulation of 2D and 3D fracture propagation processes in saturated porous media is presented. A non-local damage model is conveniently used in conjunction with interface elements to predict the degradation pattern of the domain and insert new fractures followed by remeshing. FIC-stabilized elements of equal order interpolation in the displacement and the pore pressure have been successfully used under complex conditions near the undrained-incompressible limit. A bilinear cohesive fracture model describes the mechanical behaviour of the joints. A formulation derived from the cubic law models the fluid flow through the crack. Examples in 2D and 3D, using 3-noded triangles and 4-noded tetrahedra respectively, are presented to illustrate the accuracy and robustness of the proposed methodology.
Abstract
A new computational technique for the simulation of 2D and 3D fracture propagation processes in saturated porous media is presented. A non-local damage model [...]
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Numerical analysis of side hull configuration in Trimaran
M. Heidari, Z. Razaviyan, F. Yusof, E. Mohammadian, A. Alias, M. Akhbari, A. Akbari, F. Movahedi

Rev. int. métodos numér. cálc. diseño ing. (2019). Vol. 35, (2), 32

Abstract
A trimaran is a multihull vessel designed to reduce wave-making resistances at high speeds. Optimization of the hull shape increases hull efficiency and speed of a vessel. The behavior of a ship is generally analyzed through numerical methods to save time and reduce high expenditures as compared to experimental methods. Although wide ranges of studies have investigated the hydrodynamic behavior of a vessel, the effect of trim angle, yaw angle, and heel angle of side hulls on hydrodynamic behavior of a trimaran has not been addressed properly. In the present study, a trimaran was modeled using computer-aided design software. Dimensions of the computational domain and boundary conditions were applied. Furthermore, mesh convergence was carried out. The accuracy of the method was validated. Analyses are based on the finite volume method. The analysis is carried out to obtain the resistance of side hulls and its effect on total trimaran resistance, effect of speed on hulls vessel resistance, wave patterns generated by the vessel at different trim and yaw angles, effect of trim, heel and yaw angles on side hull and total resistance of trimaran, the wetted surface at different trim, yaw, and heel angles, shape of free surface between the hulls, and the optimal position and trim angle of side hulls relative to the main hull. This computational analysis represents a step in quantifying the role of the trim, heel and yaw angles of side hulls on hydrodynamic characteristics of trimaran in calm water. The worth of information from present study may express the importance of the factors that could reduce the total resistance of a trimaran.
Abstract
A trimaran is a multihull vessel designed to reduce wave-making resistances at high speeds. Optimization of the hull shape increases hull efficiency and speed of a vessel. [...]
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Chaos control via Mathieu-Van der Pol system and Linear Optimal Control design with a non-ideal excitation and parametric uncertainties
J. Vicente, F. Chavarette, L. Roefero

Rev. int. métodos numér. cálc. diseño ing. (2019). Vol. 35, (3), 37

Abstract
In this work, a non-ideal system based on the Mathieu-Van der Pol System is modeled considering its parameters as uncertain, which makes it closer to reality. Numerical simulations are presented demonstrating that the system has a chaotic behavior with three positive Lyapunov exponents. Given such unstable and unpredictable behavior, the linear optimal control design is proposed to reduce the chaotic movement of this system to a fixed point. The simulation results show that the identification by Linear Optimal Control is very effective.
Abstract
In this work, a non-ideal system based on the Mathieu-Van der Pol System is modeled considering its parameters as uncertain, which makes it closer to reality. Numerical simulations [...]
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Regions, innovation systems, and the North-South divide in Italy
L. Leydesdorff, I. Cucco

El profesional de la información (2019). Vol. 28, (2), 88

Abstract
Innovation systems are not bound by administrative or political boundaries. Using information theory, we measure innovation-systemness as synergy among size-classes, postal addresses, and technological classes (NACE-codes) of firm-level data collected by Statistics Italy at different scales. Italy is organized in twenty regions, but there is also a traditional divide between the North and the South of the country. At which levels is how much innovation-systemness indicated? The greatest synergy is retrieved by considering the country in terms of Northern and Southern Italy as two sub-systems, with Tuscany included as part of Northern Italy. We suggest that separate innovation strategies could be developed for these two parts of the country. The current focus on regions for innovation policies may to some extent be an artifact of the statistics and EU policies. In terms of sectors, both medium- and high-tech manufacturing (MHTM) and knowledge-intensive services (KIS) are proportionally integrated in the various regions
Abstract
Innovation systems are not bound by administrative or political boundaries. Using information theory, we measure innovation-systemness as synergy among size-classes, postal [...]
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Las empresas de formación del futuro. El ejercicio de la calidad como estrategia de supervivencia
M. Fandos Igado, I. Aguaded

Educación XX1 (2009). ISSN 0211-819X

Abstract
El debate sobre la calidad en y de la educación es, además de muy interesante, muy complejo. Este trabajo aporta una reflexión sobre la misma sobre algunos ejes escasamente analizados, ya que nos adentra en una visión empresarial desde la perspectiva educativa. Las empresas de formación, como el caso concreto que analizamos, Master-D, parten, como premisa de actuación, de que la praxis concreta de la calidad es necesariamente una garantía de supervivencia, futuro y progreso.
Abstract
El debate sobre la calidad en y de la educación es, además de muy interesante, muy complejo. Este trabajo aporta una reflexión sobre la misma sobre algunos [...]
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Formación del profesorado y software social Teacher Training and Social Software
I. Aguaded, E. López Meneses

Estudios sobre educación (2010). ISSN 1578-7001

Abstract
En un mundo en el que se imponen las tecnologías de la información y la comunicación, la Universidad española tiene el reto de la adaptación al Espacio Europeo de Educación Superior con la demanda de importantes cambios estructurales y especialmente metodológicos en los procesos de enseñanza/aprendizaje. En este contexto, el software social aparece como una herramienta que, estratégicamente utilizada, puede generar consistentes innovaciones pedagógicas. En este trabajo se presenta un estudio del uso estratégico y constructivista de los blogs. Durante el curso 2008/09, alumnos de tres cursos y especialidades distintas de Magisterio de la Universidad de Extremadura compartieron prácticas y reflexionaron activamente sobre su propio proceso académico a través de los blogs. Se analizan específicamente sus concepciones sobre la introducción de las TIC y los blogs en el aula. Se detecta que cuando el alumnado tiene oportunidades para decidir algunos aspectos de su formación, ésta se hace más consciente y motivadora, y mejora sensiblemente, en este caso con el uso de tecnologías novedosas como los blogs, resultando, por ello, un importante y útil recurso pedagógico en la formación de los estudiantes.
Abstract
En un mundo en el que se imponen las tecnologías de la información y la comunicación, la Universidad española tiene el reto de la adaptación [...]
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Aprendizaje cooperativo on-line a través de foros en un contexto universitario: un análisis del discurso y de las redes
R. Tirado Morueta, Á. Hernando, I. Aguaded

Estudios sobre educación (2011). ISSN 1578-7001

Abstract
La investigación que presentamos en este artículo es el resultado de un proyecto de innovación docente, realizado a través del campus virtual de la Universidad de Huelva, en el que los sujetos fueron estudiantes de tercer curso de la Diplomatura de Educación Social que cursaban el practicum. Se presenta el análisis de los procesos de aprendizaje colaborativo en un contexto asincrónico de prácticas curriculares a través del análisis del discurso y de la densidad e intensidad de las redes sociales creadas. Esta interpretación permitirá concebir próximas experiencias e investigaciones que avancen en la concepción de indicadores de calidad para estos métodos de aprendizaje.
Abstract
La investigación que presentamos en este artículo es el resultado de un proyecto de innovación docente, realizado a través del campus virtual de [...]
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Campus virtuales en las universidades andaluzas: tipologías de uso educativo, competencias docentes y apoyo institucional
Á. Hernando, I. Aguaded

Teoría de la educación (2011). ISSN 1130-3473

Abstract
Este artículo, reflejo del Proyecto de Investigación de Excelencia «Plataformas de teleformación para la virtualización de asignaturas», muestra el estado general del uso de la enseñanza virtual en las universidades de Andalucía occidental, con el objetivo de identificar el uso educativo de las plataformas digitales actualmente en la educación superior. Mediante un cuestionario específico, se identifican variables de los recursos digitales utilizados, funcionalidades, competencias tecnológicas del profesorado y medidas institucionales. El análisis de correspondencias múltiples (ACM) permitió identificar cuatro tipos de usos educativos asociados: a) grupo mayoritario de docentes que utilizan este medio principalmente con carácter informativo y con baja competencia; b) grupo de docentes con elevada competencia que hacen un uso frecuente y extendido de las plataformas; c) grupo de profesores que utilizan ocasionalmente las plataformas en un contexto carente de medidas de impulso y sin capacitación tecnológica; y d) grupo minoritario de profesores que hacen un uso ampliado de las plataformas, con elevada competencia tecnológica y en un contexto estimulante para el uso de las TIC.
Abstract
Este artículo, reflejo del Proyecto de Investigación de Excelencia «Plataformas de teleformación para la virtualización de asignaturas», [...]
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The effect of centralization and cohesion on the social construction of knowledge in discussion forums
R. Tirado Morueta, Á. Hernando, I. Aguaded

Interactive learning environment (2012). ISSN 1445-1917

Abstract
Interactive relationships in online learning communities can influence the process and quality of knowledge building. The aim of this study is to empirically investigate the relationships between network structures and social knowledge building in an asynchronous writing environment through discussion forums in a learning management system. The quality of the knowledge construction process is evaluated through content analysis, and the network structures are analyzed using a social network analysis of the response relations among participants during online discussions. Structural equation modeling is used to analyze relations between network structures and knowledge construction. Working on data extracted from a 6-week distance-learning experiment, we analyzed how 10 groups developed collaborative learning social networks when participants worked together on case resolution. The results show a positive correlation between cohesion and centralization, and the positive influence of the cohesion index and the centralization index on social presence and cognitive presence in knowledge building. However, this must be understood within the context of social networks in which messages sent to all group members occupy the center. This underlines the need for reinforcing participations that are directed to the group as a whole, and the importance of the fact the network contains both central and intermediate members. By contrast, we propose that the combination of analysis techniques used is a good option for this type of study while recognizing that it is necessary to continue validating the instruments in terms of their own theoretical suppositions.
Abstract
Interactive relationships in online learning communities can influence the process and quality of knowledge building. The aim of this study is to empirically investigate the [...]
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Incidencia de los hábitos de ocio y consumo de drogas sobre las medidas de prevención de la drogadicción en universitarios
I. Gutiérrez, I. Aguaded

Educación XX1 (2013). ISSN 1139-613X

Abstract
A partir de variables relativas a la ocupación del tiempo de ocio y sus hábitos de consumo de drogas, este estudio se propone identificar diferentes subgrupos de estudiantes universitarios que permitan definir estrategias que eviten el inicio del consumo de drogas y su reducción ajustadas a sus preferencias e intereses. Utilizando como método de clasificación de conglomerados K medias se identifican seis conglomerados de estudiantes bien diferenciados entre sí e internamente estables en función de sus hábitos de consumo de drogas y ocupación del tiempo de ocio. A continuación se aplica el test de chi cuadrado de Pearson, encontrándose relaciones significativas entre la variable tipo de conglomerado y las estrategias preventivas preferidas. Finalmente, el análisis de regresión logística binaria permite identificar estrategias preventivas favorables y desfavorables según el conglomerado. En conclusión, se observan relaciones de dependencia entre los hábitos de consumo y ocupación del tiempo de ocio de cada subgrupo. La oferta cultural y deportiva se entiende como una medida atractiva para subgrupos de estudiantes que practican deporte y/o disfrutan con la actividad cultural, mientras que conglomerados más pasivos prefieren la oferta de asignaturas con propósitos preventivos. No obstante, todo ello ha de entenderse en el marco de una estrategia de prevención universal consciente de la pluralidad de la comunidad universitaria y atenta a sus demandas.
Abstract
A partir de variables relativas a la ocupación del tiempo de ocio y sus hábitos de consumo de drogas, este estudio se propone identificar diferentes subgrupos [...]
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El grado de competencia mediática en la ciudadanía andaluza
J. Sánchez Carrero, I. Aguaded

Estudios sobre el mensaje periodístico (2013). ISSN 1134-1629

Abstract
Conocer el grado de competencia mediática de la ciudadanía es hoy un reto crucial para entender la sociedad de la información en la que estamos inmersos y, por ende, una tarea imprescindible para establecer acciones formativas en alfabetización mediática. Este trabajo recoge los resultados globales de investigación obtenidos en una variada muestra de la ciudadanía andaluza y e inserto en un amplio estudio realizado a nivel estatal durante los últimos años con la implicación de las 17 Comunidades Autónomas y abanderado por el Consejo Audiovisual de Cataluña. El estudio define, en primer lugar, el polisémico término competencia mediática para luego segmentarlo en sus seis dimensiones clave: estética, lenguaje, ideología y valores, tecnología, producción y programación, y recepción y audiencia. La presente investigación concluye que la población que constituye la muestra carece de competencia mediática en dichas dimensiones, por lo se hace necesaria la integración de una asignatura educación mediática en el currículo escolar.
Abstract
Conocer el grado de competencia mediática de la ciudadanía es hoy un reto crucial para entender la sociedad de la información en la que estamos inmersos [...]
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Influencias de las creencias del profesorado sobre el uso de la tecnología en el aula
R. Tirado Morueta, I. Aguaded

Revista de educación (2014). ISSN 0034-592X

Abstract
Esta investigación, enmarcada en un proyecto I+D+i financiado por el Gobierno de España, tiene por objetivo comprobar cómo las creencias del profesorado sobre el significado y sentido de la tecnología en la educación actúan a modo de factores impulsores o, por el contrario, a modo de barreras para el uso de la tecnología en centros educativos. Metodológicamente, para mostrar estas influencias se elabora un cuestionario basado en las concepciones teóricas sobre la tecnología planteadas por Aviram y Richarson; tiene una consistencia interna (alfa de Crombach) de 0,869. Se realizan un análisis de regresión logística (RL) y un análisis de correspondencias múltiples (ACM) de los datos obtenidos a partir de una muestra de 324 profesores pertenecientes a los primeros centros TIC andaluces, en el marco de las medidas de impulso promovidas por el Gobierno de la Comunidad Autónoma de Andalucía desde 2002. El análisis factorial previo a la RL permite diferenciar cuatro factores (creencias) que se denominan ad hoc: sociorreformista, contrarios a la tecnología, críticos y humanistas. Asimismo, el ACM, permite diferenciar tres grupos de profesores: sociorreformistas, sociorreformistas moderados y profesores sin opinión sobre la tecnología. Los resultados de la RL muestran una influencia positiva de las creencias etiquetadas como sociorreformistas en la frecuencia de uso de las TIC, mientras que las creencias contrarias y críticas muestran una clara influencia negativa. Asimismo, el ACM permite comprobar que el grupo de profesores con creencias sociorreformistas es el que está más próximo, en el plano factorial, al uso regular de las TIC en el aula. Finalmente, se sugieren líneas de investigación que profundicen en el problema y permitan abordarlo integralmente.
Abstract
Esta investigación, enmarcada en un proyecto I+D+i financiado por el Gobierno de España, tiene por objetivo comprobar cómo las creencias del profesorado [...]
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La TV por IP en la Universidad: Un reto de divulgación científica televisiva para jóvenes chilenos
I. Aguaded

Estudios sobre el mensaje periodístico (2014). ISSN 1134-1629

Abstract
Diseñar nuevos modelos de televisión en el contexto de la sociedad digital se convierte en una necesidad desde el ámbito de la investigación y la academia. El presente trabajo analiza los intereses y necesidades de información expresados por jóvenes espectadores chilenos, con el objeto de diseñar una IPTV universitaria, modalidad de TV por Internet, que incorpora, mediante las múltiples interacciones que genera Internet los contenidos audiovisuales preferidos por dicho público meta, con énfasis en lo cultural y educativo. Los jóvenes chilenos están de acuerdo en que el nuevo medio prevalecerá sobre los demás y contribuirá a la adquisición de nuevos saberes, procedimientos y utilidades para ser utilizados en la vida cotidiana, así como al incremento de la cultura científica y su participación ciudadana activa
Abstract
Diseñar nuevos modelos de televisión en el contexto de la sociedad digital se convierte en una necesidad desde el ámbito de la investigación y [...]
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