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Start Over Topic mathematical optimization Topic structural analysis (engineering) Publication Type Books Publication Type Magazines
4 results

1. Truss Topology Optimization Using Genetic Algorithm with Individual Identification Technique.

Author

Su Ruiyi, Gui Liangjin, and Fan Zijie

Subjects
*TOPOLOGY, *MATHEMATICAL optimization, *GENETIC algorithms, *ALGORITHMS, *COMPUTATIONAL complexity, *STRUCTURAL analysis (Engineering)
Abstract

Since the evaluation of each individual is based on the time-consuming structural analysis, the computational efficiency of truss topology optimization using genetic algorithm is very low. The paper focuses on this challenging problem. It is observed that there are a number of duplicate individuals appearing repetitively in the evolutionary process. Therefore, an individual identification technique is introduced to avoid evaluating the duplicate individuals by the time-consuming structural analysis but by searching the evolutionary history data to save computing time, the computational complexity of this technique is deduced. The results of two truss examples verify that the technique can effectively improve the efficiency of the algorithm. Based on this identification technique, numeric experiments are implemented to study the influence of several factors, i.e., the population size, the max generation, and the scale of problems, on the proportion of duplicate individuals. Results show that the population size has a significant impact on the proportion, and that both the max generation and the scale of problems have little influence. [ABSTRACT FROM AUTHOR]

Published
2009

2. Comparative Strength of Common Structural Shapes Using Genetic Algorithms.

Author

Nadela, Federico M. and Lope, Jose Ernie C.

Subjects
*GENETIC algorithms, *STRENGTH of materials, *STRUCTURAL analysis (Engineering), *MATHEMATICAL optimization, *COMBINATORIAL optimization, MATHEMATICAL models of uncertainty
Abstract

The motivation for this paper is to develop an approach to optimization of beam design. Under given loading and support conditions, the comparative strength of three (3) common structural shapes was determined. This led to the conclusion that a particular structural shape together with its dimensions will give the optimal solution in beam design in terms of the least cross-sectional area to support the given load, which would then translate to savings in cost and reduction in weight of the structural member. An investigation was also conducted to take into consideration the effect in the dimensions of the structural shapes of uncertainties due to manufacturing limitations and tolerances. This resulted in an assessment of the order of magnitude of this effect on the design variables. In solving the resulting optimization problems, MATLAB's Genetic Algorithm and Direct Search Toolbox was employed. [ABSTRACT FROM AUTHOR]

Published
2009

3. Correlation between hole insertion criteria in a boundary element and level set based topology optimisation method.

Author

Ullah, B. and Trevelyan, J.

Subjects
*STATISTICAL correlation, *BOUNDARY element methods, *TOPOLOGY, *MATHEMATICAL optimization, *LEVEL set methods, *STRUCTURAL analysis (Engineering)
Abstract

Abstract: The research work presented in this paper is based on the correlation between two hole insertion criteria in a boundary element method (BEM) and level set method (LSM) based structural topology optimisation scheme for 2D elastic problems. The hole insertion criteria used in this work are based on the von Mises stress and the topological derivative approaches. During the optimisation process holes are automatically inserted in the design domain using each of the two criteria. The LSM is used to provide an implicit description of the structural geometry, and is also capable of automatically handling topological changes, i.e. holes merging with each other or with the boundary. The evolving structural geometry (i.e. the zero level set contours) is represented by NURBS, providing a smooth geometry throughout the optimisation process and completely eliminate jagged edges. In addition the optimal NURBS geometry can be used directly in other design processes. Four different benchmark examples are considered in this study and each is tested against the two hole insertion criteria. The results obtained validate the proposed optimisation method and we demonstrate a clear correlation between the two hole insertion criteria. [Copyright &y& Elsevier]

Published
2013
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4. Topological derivatives for optimization of plane elasticity contact problems

Author

Sokołowski, Jan and Żochowski, Antoni

Subjects
*ELASTICITY, *BOUNDARY value problems, *TOPOLOGY, *STRUCTURAL analysis (Engineering), *MATHEMATICAL optimization, *CONTACT mechanics
Abstract

Abstract: Topological derivatives for plane elasticity problems are used in shape and topology optimization in structural mechanics. We propose an approach to the asymptotic analysis of singular perturbations of geometrical domains. This approach can be used in order to determine the exact solutions to elasticity boundary value problems in domains with small holes and determine the explicit asymptotic expansions of solutions with respect to small parameter, which describes the radius of internal hole. The elastic potentials of Muskhelishvili give us an explicit solution in the ring in the form of complex valued series. The series depends on the small parameter, the radius of the ring, and we are interested in the behavior of the series for the passage . Such analysis leads to the expansion of the elastic energy in the form where is used to determine the first-order topological derivatives of shape functionals, and can be used to determine the second-order topological derivatives of shape functionals. In this paper the first-order term is given; however, the method is general and can be used to determine the subsequent terms of the energy expansion and the topological derivatives of higher order. [Copyright &y& Elsevier]

Published
2008
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