Documents published in Scipedia

• Intelligent Initiatives to Reduce CO2 Emissions in Construction

  L. Farahzadi, M. Kioumarsi

  eccomas2022.

  
  

  Abstract
  Global warming is one of the most important environmental issues that threatens the living on this globe so far.

  • 19
  •  read

• Seismic performance of dissipative automated rack supported warehouses

  A. Natali, F. Morelli

  eccomas2022.

  
  

  Abstract

  In this paper, performance of dissipative reduced-section diagonals implemented in Automated Rack Supported Warehouses (ARSWs) is analysed. ARSWs are storage systems where the steel racks traditionally used to store goods only, constitute also the primary system of the building. Given the lack of a reference design code to design these structures as seismicresistant, and starting from a critical analysis of the current design approaches, a proper design strategy for these structures has been developed, which is based on the possibility to dissipate seismic energy in the bracings. However, the design of an over-resistant connection that would allow the yielding of the bracings is quite tricky due to the very low thickness of the elements usually adopted for these structures and is only possible by reducing the cross section of the profile. A wide experimental campaign is preformed to validate the behaviour of these diagonals, to be later implemented in the global numerical model of the structure to measure the effective performances of the case study ARSWs, both at local and global level.

  Abstract
  In this paper, performance of dissipative reduced-section diagonals implemented in Automated Rack Supported Warehouses (ARSWs) is analysed. ARSWs are storage systems where [...]

  • 5
  •  read

• Seismic performance of an innovative dissipative replaceable components bracing steel frame (DRBrC)

  S. Caprili, F. Mattei, W. Salvatore

  eccomas2022.

  
  

  Abstract

  The structural performance of a steel Concentrically Braced Frame (CBF) equipped with replaceable dissipative seismic components, called DRBrC, is presented. X-diagonal CBFs are an efficient structural solution for buildings in seismic prone areas, being conceived to dissipate the energy stored during the earthquake through plastic deformation of bracing elements; all the other components remain in the elastic field thanks to opportune design criteria. Of course, structural damages, even if voluntarily located in specific regions, need to be repaired after the seismic event to restore the functionality of the building, leading to relevant economic (and time) effort since the full replacement of damaged dissipative components is necessary after irreversible plastic deformations. Recently, research activities have been widely carried out to provide repairability of steel buildings by means of easily replaceable dissipative components. The Research Fund for Coal and Steel (RFCS) of European Commission, for instance, promoted and funded the research project DISSIPABLE Fully dissipative and easily reparable device for resilient buildings with composite steel-concrete structure', with the aim of designing, producing, optimizing and testing several dissipative components for steel structures having, as fundamental feature, the full repairability after the earthquake without impacting on other components. In the present paper, the seismic performance of a steel braced frame equipped with a specific typology of dissipative replaceable device at the ends of braces is presented by means of nonlinear analyses.

  Abstract
  The structural performance of a steel Concentrically Braced Frame (CBF) equipped with replaceable dissipative seismic components, called DRBrC, is presented. X-diagonal CBFs [...]

  • 4
  •  read

• Comparing three calculation methods of load distribution in radial bearings

  M. Ricci

  eccomas2022.

  
  

  Abstract

  There are two basic methods for radial external load distribution calculation on rolling elements in a rolling element bearing: the discrete method and the integral method. Solving the discrete equilibrium equation using the Newton-Raphson scheme, more accurate results are derived than those based on the integral method, with small theoretical and computational efforts. The Sjövall's radial integral factors, as well as some approximations proposed in the literature, for lineand point-contacts, are given. Numerical approximations for the Sjövall's radial integrals are proposed. The approximations' errors with respect to the Sjövall's radial integral's numerical integration are shown.

  Abstract
  There are two basic methods for radial external load distribution calculation on rolling elements in a rolling element bearing: the discrete method and the integral method. [...]

  • 25
  •  read

• Investigation of parameter-dependent material characteristics of additively manufactured specimens for data-driven part optimization

  D. Zettel, P. Breitkopf, P. Nicolay, R. Willmann

  eccomas2022.

  
  

  Abstract

  Direct Metal Laser Sintering (DMLS) is a complex production process including hosts of parameters and a multitude of physical phenomena, which make the simulation and modeling quite challenging. This work investigates the impact of modified printing parameters (e.g., hatch distance, laser power) on correlating material properties (e.g., Young's modulus, temperature gradient) of hardened aluminum specimens. The ultimate goal is to create a data model that enables data-driven and multi-physical optimization of mechanical components fabricated via DMLS.

  Abstract
  Direct Metal Laser Sintering (DMLS) is a complex production process including hosts of parameters and a multitude of physical phenomena, which make the simulation and modeling [...]

  • 4
  •  read

• On different discretisation strategies to solve the kinematical and equilibrium problem for masonry-like structures

  A. Montanino, C. Olivieri, D. Gregorio, A. Iannuzzo

  eccomas2022.

  
  

  Abstract

  Nowadays, there is a raising interest in the development of fast and robust tools to detect the consequences of settlements or loading changes in unreinforced masonry buildings, since they constitute a large part of world architectural heritage. Current tools, based on Finite Element Method or on Discrete Element Method are computationally cumbersome, from one side due to difficulties in dealing with unilateral materials, and on the other side, due to the need of formulating the problem as an explicit dynamics problem. The methods proposed here are based on the minimization problem of two different functionals, the Total Potential Energy, and the Total Complementary Energy, which allow to detect the stress and strain distribution developed under given load and given boundary settlements, through a minimization problem, which require a significantly lower computational cost and no material parameters, especially when rigidity assumption of the material is done. After illustrating the main characteristics of the two methods, they are applied to a case study, and the results are suitably described and discussed.

  Abstract
  Nowadays, there is a raising interest in the development of fast and robust tools to detect the consequences of settlements or loading changes in unreinforced masonry buildings, [...]

  • 5
  •  read

• Robust discretizations for poroelastic problems: engineering and mathematical points of views in a presenation in pairs

  M. Brodbeck, F. Bertrand

  eccomas2022.

  
  

  Abstract

  This contribution is the proceeding of a presentation in pairs taking different viewpoints on the robustness of discretizations for poroelastic problems. These presentations are organised by the Young researcher committee to continue the tradition of fruitful interactions between applied mathematics and computational engineering. The engineering part of this contribution highlights key aspects of the theoretical framework and comments on robustness of common discretizations. Within the mathematical part of this contribution it is shown that the accurate approximation of the total stress tensor as well as the Darcy velocity are crucial to obtain reliability and robustness.

  Abstract
  This contribution is the proceeding of a presentation in pairs taking different viewpoints on the robustness of discretizations for poroelastic problems. These presentations [...]

  • 7
  •  read

• Transonic Buffet Simulation using a Partially-Averaged Navier-Stokes Approach

  A. Petrocchi, R. Steijl, G. Barakos

  eccomas2022.

  
  

  Abstract

  This work assesses the capability of the partially averaged Navier-Stokes (PANS) method to accurately reproduce self-sustained shock oscillations, also known as transonic buffet, occurring on supercritical aerofoils at high Reynolds numbers. Attention is paid to the comparison with unsteady Reynolds-averaged Navier Stokes (URANS) results to show the benefits of PANS, in resolving flow unsteadiness on affordable CFD grids. The role of the mesh metrics in the formulation of the PANS model is emphasized, as well as the relation of the mesh metrics with the spatiotemporal discretisation used for the numerical simulations. The aim is to extend the use of PANS to flow cases involving shock-wave boundary layer interactions to obtain accurate predictions without the need for very expensive computations.

  Abstract
  This work assesses the capability of the partially averaged Navier-Stokes (PANS) method to accurately reproduce self-sustained shock oscillations, also known as transonic [...]

  • 11
  •  read

• Review of Micro and Mesoscale simulation methods for Laser Powder Bed Fusion

  A. Gopaluni, H. Piili, A. Salminen

  eccomas2022.

  
  

  Abstract

  Additive manufacturing (AM) is an advanced method of manufacturing complex parts layer by layer until the required design is achieved. Laser powder bed fusion (L-PBF) is used to produce parts with high resolution because of low layer thickness. L-PBF is based on laser beam and material interaction where the powder material is melted and then solidified. This occurs in a short time frame of the order of 0.02 seconds and makes the whole process challenging to be studied in real time. Studies have shown the development of numerical methods and the use of simulation software to understand the laser beam and material interaction. This phenomenon is key to understanding the material behavior under melting and mechanical properties of the part produced by L-PBF process as it is directly linked with the solidification of the melted powder material. A detailed study of the laser beam and material interaction is needed on a microscale and mesoscale level as it provides a better understanding and helps in the development of the given material for the L-PBF process. This review provides a comprehensive understanding of the background for the use of simulation in AM and the different simulation scales of feature under interest. The main conclusion from this review is the need to develop a methodology to use simulation at micro and mesoscale level to understand the laser beam and material interaction and improve the efficiency of the L-PBF process using this data.

  Abstract
  Additive manufacturing (AM) is an advanced method of manufacturing complex parts layer by layer until the required design is achieved. Laser powder bed fusion (L-PBF) is used [...]

  • 28
  •  read

• Strategic application of digital tools to enhance lifecycle cost: product design and optimization in metal based powder bed fusion

  P. Nyamekye, R. Lakshmanan, H. Piili

  eccomas2022.

  
  

  Abstract

  Additive manufacturing (AM) has undergone different phases of technological changes from being a mere manufacturing method for consumer goods, prototyping, and tooling to industrial series production of functional end-use parts. The seven AM sub-categories allow the creation of unprecedented designs that are otherwise impossible using conventional manufacturing (CM) methods. The layer-by-layer approach to manufacturing enables the creation of metal components with hollows and overhangs, often requiring sacrificial support structures which are removed prior to or during the post-processing phase. Factors such as poor part quality, high investment cost, low material efficiency, and long manufacturing time hindered the widespread adoption of AM in the past. The adoption of laser-based powder bed fusion for metals was particularly hindered due to reasons such as the need for support structures, demand for post-processing, the numerous affecting processing parameters and the lack of understanding of the interaction between laser beam and material. Technological advances in AM have helped users reduce or omit some of the limitations to adoption, such as optimized support structures for better material efficiency. Simulation-driven tool is one means offering ways to time-efficient product development and more superior structural components amidst the raw material and cost reductions. This study elucidates how such benefits are feasible via using simulation tools. Simulation-driven optimization of the product design, process, and manufacturing is revealed to change the design, support structures and postprocessing required to bring parts to the required reliability. Virtual manufacturing planning also gives a prior understanding of how processing parameters such as laser scan velocity, laser power, scanning strategy, hatch distance and others can be controlled; to achieve optimal interaction between laser beam and material for the required part quality. Simulation-driven design for additive manufacturing (DfAM) allows for agile design optimizing with design parameters and rules, boosting resource efficiency and productivity. This research proposes a life cycle cost (LCC)driven DfAM tool, which potentially improves service life and life cycle cost. The results provide insight into the simulation-driven DfAM of laser-based PBF and demonstrate the potential for LCC-based approaches to enhance the confidence in adopting PBF for metals.

  Abstract
  Additive manufacturing (AM) has undergone different phases of technological changes from being a mere manufacturing method for consumer goods, prototyping, and tooling to [...]

  • 31
  •  read