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• Estimation of peak flow in flood-producing rivers using numerical simulation, geospatial information and evolutionary algorithms

  H. Esqueda, S. Botello, S. Valdez

  Rev. int. métodos numér. cálc. diseño ing. (Online first).

  
  

  Abstract

  Floods produce enormous human and material losses every year. Evaluating their extent and severity, and especially simulating possible future scenarios can improve the response, mitigation and prevention of the effects of this phenomenon. This paper presents a methodology to reproduce the extent of floods produced by channel overflows and recorded by satellite images, identifying the maximum discharge that produced it by means of the numerical solution of the 2D shallow water equations and Differential Evolution. The objective is to minimize the difference between the extent of the flooded area recorded in the satellite images, and that obtained in the simulation by adjusting the maximum value of the flow curve used at the entrance of the channel in the solution domain. The proposal is applied to data and images corresponding to an area located south of the city of Villahermosa, in the Mexican state of Tabasco, which is an area susceptible to flooding by the overflow of the Río de la Sierra. Our proposal shows that it is possible to have more accurate information on the extent and height of water in the flooded area than that shown by the satellite, which can be used as information for prevention and mitigation plans for the adverse effects of flooding. Palabras clave: Modelado de inundaciones, gasto máximo en ríos, Iber, evolución diferencial

  Abstract
  Floods produce enormous human and material losses every year. Evaluating their extent and severity, and especially simulating possible future scenarios can improve the response, [...]

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• Anisotropy in 2D Discrete Exterior Calculus

  . , H. Esqueda, R. Herrera, S. Botello, C. Valero

  Collection title not available (2020). 1

  
  

  Abstract

  We present a local formulation for 2D Discrete Exterior Calculus (DEC) similar to that of the Finite Element Method (FEM), which allows a natural treatment of material heterogeneity (assigning material properties element by element). It also allows us to deduce, in a principled manner, anisotropic fluxes and the DEC discretization of the pullback of 1-forms by the anisotropy tensor, i.e. we deduce the the discrete action of the anisotropy tensor on primal 1-forms. Due to the local formulation, the computational cost of DEC is similar to that of the Finite Element Method with Linear interpolating functions (FEML). The numerical DEC solutions to the anisotropic Poisson equation show numerical convergence, are very close to those of FEML on fine meshes and are slightly better than those of FEML on coarse meshes.

  Abstract
  We present a local formulation for 2D Discrete Exterior Calculus (DEC) similar to that of the Finite Element Method (FEM), which allows a natural treatment of material heterogeneity [...]

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• Solving anisotropic Poisson problems via discrete exterior calculus

  H. Esqueda, R. Herrera, S. Botello, C. Valero

  Rev. int. métodos numér. cálc. diseño ing. (2020). Vol. 36, (2), 32

  
  

  Abstract

  We present a local formulation for 2D Discrete Exterior Calculus (DEC) similar to that of the Finite Element Method (FEM), which allows a natural treatment of material heterogeneity (assigning material properties element by element). It also allows us to deduce, in a principled manner, anisotropic fluxes and the DEC discretization of the pullback of 1-forms by the anisotropy tensor, i.e. we deduce the the discrete action of the anisotropy tensor on primal 1-forms. Due to the local formulation, the computational cost of DEC is similar to that of the Finite Element Method with Linear interpolating functions (FEML). The numerical DEC solutions to the anisotropic Poisson equation show numerical convergence, are very close to those of FEML on fine meshes and are slightly better than those of FEML on coarse meshes.

  Abstract
  We present a local formulation for 2D Discrete Exterior Calculus (DEC) similar to that of the Finite Element Method (FEM), which allows a natural treatment of material heterogeneity [...]

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• Optimization method for the determination of material parameters in damaged composite structures

  E. Comellas, S. P, S. Oller, S. Botello

  Composite Structures (2015). (preprint) Vol. 122, pp. 417-424

  
  

  Abstract

  An optimization method to identify the material parameters of composite structures using an inverse method is proposed. This methodology compares experimental results with their numerical reproduction using the finite element method in order to obtain an estimation of the error between the results. This error estimation is then used by an evolutionary optimizer to determine, in an iterative process, the value of the material parameters which result in the best numerical fit. The novelty of the method is in the coupling between the simple genetic algorithm and the mixing theory used to numerically reproduce the composite behavior. The methodology proposed has been validated through a simple example which illustrates the exploitability of the method in relation to the modeling of damaged composite structures.

  Abstract
  An optimization method to identify the material parameters of composite structures using an inverse method is proposed. This methodology compares experimental results with [...]

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• Métodos avanzados de cálculo de estructuras de materiales compuestos

  E. Oñate, S. Oller, S. Botello, J. Miquel

  Monograph CIMNE (1991). M3

  
  

  Abstract

  Se presenta una panorámica del estado del arte de los métodos más actuales para análisis de estructuras con materiales compuestos, incidiendo particularmente en los métodos para análisis de vehículos industriales como materiales compuestos

  Abstract
  Se presenta una panorámica del estado del arte de los métodos más actuales para análisis de estructuras con materiales compuestos, incidiendo particularmente [...]

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• Método Numérico Basado en Cálculo Exterior Discreto Para la Discretización de la Ecuación de Convección - Difusión

  M. Noguez, S. Botello, R. Herrera

  Revista Mexicana de Métodos Numéricos (2019). Vol. 3, 4

  
  

  Abstract

  Mientras que la discretización con Cálculo Exterior Discreto (DEC) del término elíptico de la ecuación de Transporte, también conocida como la Ecuación de Convección - Difusión, está bien documentada y establecida, la discretización del término convectivo, así como su estabilización siguen siendo un tema de investigación. En este trabajo se propone una discretización local de la Ecuación de Transporte homogénea, isótropa y con flujo incompresible, basada en DEC y fundamentada en argumentos geométricos. Debido a que el método numérico obtenido para el termino convectivo es similar al de Elemento Finito con funciones de interpolación lineales (FEML), se pueden aprovechar algunas técnicas conocidas para la estabilización de la ecuación. Empleando esta característica, las pruebas numéricas se llevan a cabo en mallas que varían de gruesas a finas para comparar los resultados obtenidos con DEC y FEML, y para mostrar convergencia numérica en problemas estacionarios. La estabilización de la ecuación es llevada a cabo mediante Difusión Artificial.

  Abstract
  Mientras que la discretización con Cálculo Exterior Discreto (DEC) del término elíptico de la ecuación de Transporte, también conocida [...]

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• Simulación numérica del choque de vehículos por el método de los elementos finitos

  E. Oñate, S. Botello

  (1991). Research Report, Nº PI17

  
  

  Abstract

  En este trabajo se presentan las principales características del programa de ordenador “IMPACT 3D” actualmente en desarrollo en el Centro Internacional de Métodos Numéricos en Ingeniería de Barcelona para la simulación numérica de problemas de impacto y choque de vehículos. El programa se basa en una formulación de elementos finitos de lámina no lineal incorporando también elementos de sólidos y de viga para modelar correctamente todos los componentes resistente típico de estructuras de vehículos. El programa permite la utilización de algoritmos de integración en el tiempo explícitos e implícitos incluyendo además modelos constitutivos para materiales compuestos. Los ejemplos que se presentan muestran la aplicación del programa a la deformación de una puerta sometida a un ensayo penetración lateral y el choque frontal de un prototipo de vehículo industrial.

  Abstract
  En este trabajo se presentan las principales características del programa de ordenador “IMPACT 3D” actualmente en desarrollo en el Centro Internacional [...]

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• CALSEF: Programa para cálculo estático lineal de sólidos y estructuras para el método de elementos finitos

  E. Oñate, S. Botello

  (1992). Research Report, Nº PI18

  
  

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• An anisotropic elastoplastic model based on an isotropic formulation

  S. Oller, S. Botello, J. Canet, E. Oñate

  (1993). Research Report, Nº PI41

  
  

  Abstract

  This paper shows a generalization of the classic isotropic plasticity theory to be applied to orthotropic or anisotropic materials. This approach assumes the existence of a real anisotropic space, and other fictitious isotropic space where a mapped fictitious problem is solved. Both spaces are related by means of a linear transformation using a fourth order transformation tensor that contains all the information concerning the real anisotropic material. The paper describes the basis of the spaces transformation proposed and the expressions of the resulting secant and tangent constitutive equations. Also details of the numerical integration of the constitutive equation are provided. Examples of application showing the good performance of the model for analysis of orthotropic materials and fibre‐reinforced composites are given.

  Abstract
  This paper shows a generalization of the classic isotropic plasticity theory to be applied to orthotropic or anisotropic materials. This approach assumes the existence of [...]

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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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