Solving structural optimization problems with genetic algorithms and simulated annealing

In this paper we study the performance of two stochastic search methods: Genetic Algorithms and Simulated Annealing, applied to the optimization of pin‐jointed steel bar structures. We show that it is possible to embed these two schemes into a single parametric family of algorithms, and that optimal performance (in a parallel machine) is obtained by a hybrid scheme. Examples of applications to the optimization of several real steel bar structures are presented

A layer-wise triangle for analysis of laminated composite plates and shells

The paper presents a new triangle for analysis of laminate plates and shells. The in-plane degrees of freedom are interpolated quadratically whereas a linear layer-wise approximation is chosen for the normal displacement. A substructuring technique is used to eliminate the in-plane degrees of freedom during the assembly process thus reducing substantially the computationed costs. The element performance is evaluated in the static and dynamic analysis of di€erent laminate plate and shell structure

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

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

A geometric description of Discrete Exterior Calculus for general triangulations

We revisit the theory of Discrete Exterior Calculus (DEC) in 2D for general triangulations, relying only on Vector Calculus and Matrix Algebra. We present DEC numerical solutions of the Poisson equation and compare them against those found using the Finite Element Method with linear elements (FEML).Peer Reviewe

A geometric description of Discrete Exterior Calculus for general triangulations

We revisit the theory of Discrete Exterior Calculus (DEC) in 2D for general triangulations, relying only on Vector Calculus and Matrix Algebra. We present DEC numerical solutions of the Poisson equation and compare them against those found using the Finite Element Method with linear elements (FEML).Comment: We made some corrections, included one more example and added several figure

A plastic damage constitutive model for composite materials

In this paper a generalized elasto-plastic damage model for the analysis of multiphase frictional composite materials is presented. Details of the derivation of the secant and tangent constitutive equations are given. Mixing theory is used to insert the basic constitutive expressions for each substance on the multiphase composite solid. Details of the numerical implementation of the model into a general non-linear finite element solution scheme are presented. Some examples of linear and non-linear behaviour of composites are given

Un modelo de elementos finitos con aproximación bidimensional por capas para el análisis de estructuras multilaminares

En este trabajo se presenta un modelo de elementos finitos con una aproximación. bidimensional por capas para el análisis de estructuras multilaminares tipo placa y lámina, plana en regímenes estático y dinámico. El elemento triangular desarrollado está basado en un elemento degenerado de 3D utilizando un campo de deformaciones impuestas de cortante. Las variables a través del espesor son eliminadas utilizando una técnica de condensación de variables. Se presentan ejemplos de aplicación de la formulación propuesta.A layer-wise finite element model for the analysis of composite plate and shell structures under static and dynamic loading is presented. The triangular element used is based on. degenerate solid theory and an assumed shear strain approach. The thickness variable are eliminated using a substructuring technique. Examples of application showing the good. performance of the formulation are given.Peer Reviewe