Otimização de estruturas reticuladas planas com comportamento geometricamente não linear

• Ano de defesa: 2006
• Autor(a) principal: ASSIS, Lilian Pureza de
• Orientador(a): ALMEIDA, Sylvia Regina Mesquita de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Mestrado em Engenharia Civil
• Departamento: Engenharias
• País: BR
• Palavras-chave em Português: Otimização; programação quadrática seqüencial; algoritmo de pontos interiores; branch and bound; análise não linear geométrica; pórticos planos; colunas estaiadas; 1. Estruturas Otimização 2. Programação quadrática seqüencial 3. Algoritmo de pontos interiores 4. Análise não linear geométrica 5. Pórticos planos 6. Colunas estaiadas
• Palavras-chave em Inglês: Optimization; sequential quadratic programming; interior points algorithm; branch and bound; non linear geometric analysis; plane frames; cable stayed columns
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS::ENGENHARIA CIVIL::ESTRUTURAS
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tde/678

The aim of this work is to present a formulation and corresponding computational implementation for sizing optimization of plane frames and cable-stayed columns considering geometric non liner behavior. The structural analysis is based on the finite element method using the updated lagrangian approach for plane frame and cable elements, which are represented by plane truss elements. The non linear system is solved by the Newton-Raphson method coupled to load increment strategies such as the arch length method and the generalized displacement parameter method, which allow the algorithm to transpose any critical point that happen to appear along the equilibrium path. In the optimization process the design variables are the heights of the crosssection of the frame elements, the objective function represents the volume of the structure and the constraints impose limits to displacements and critical load. Lateral constraints impose limits to the design variables. The finite difference method is used in the sensitivity analysis of the displacement and critical load constraints. The optimization process is carried out using three different optimization strategies: the sequential quadratic programming algorithm; the interior points algorithm; and the branch and bound method. Some numerical experiments are carried out so as to test the analysis and the sensitivity strategies. Numerical experiments are presented to show the validity of the implementation presented in this dissertation.