DOI
10.11606/D.18.2015.tde-08042015-162639
Documento
Autor
Nome completo
Sérgio Gustavo Ferreira Cordeiro
Área do Conhecimento
Data de Defesa
Imprenta
São Carlos, 2015
Leonel, Edson Denner (Presidente)
Canto, Rodrigo Bresciani
Palermo Junior, Leandro
Título em português
Formulações do método dos elementos de contorno aplicadas à análise elástica e à fratura coesiva de estruturas compostas planas
Palavras-chave em português
Estruturas compostas
Meios anisotrópicos
Método dos elementos de contorno
Modelo coesivo de fratura
Técnica de multi-regiões
Resumo em português
Título em inglês
Boundary element method formulations applied to elastic analysis and cohesive fracture of plane composed structures
Palavras-chave em inglês
Anisotropic medias
Boundary element method
Cohesive fracture model
Composed structures
Multi-region technique
Tangent operator
Resumo em inglês
The present work deals the development of numerical formulations to evaluate the mechanical behaviour of plane composed structures, in the context of linear elasticity and nonlinear fracture mechanics. The proposed formulations are based on the Boundary Element Method (BEM), through its classical singular and hyper singular integral equations. The multi-region technique is adopted to couple the interfaces of non-homogeneous multiphase bodies. The BEM is a robust and accurate numerical technique to analyse fracture phenomena in solids. This numerical method presents a mesh dimensionality reduction, which makes easier the modelling of cracks surfaces. Besides, this dimensionality reduction also makes the treatment of interfaces in composed structures a less complex task. Considering the use of Kelvin fundamental solutions at the integrals equations, isotropic materials can be represent as parts of the composed structures. On the other hand, using Cruse & Swedlow fundamental solution it is also possible to deal with general anisotropic materials. At the composed structures, cracks can propagate along the materials interfaces and the cohesive crack model is responsible for the nonlinear structural behaviour of the quasi-brittle failures. The nonlinear system of equations at the fracture analyses is solved using two different algorithms for iterative resolution. The first always takes into account the structure elastic strength and, hence it is called Constant Operator (CO). On the other hand, the second is denominated Tangent Operator (TO) due to the fact that it considers strengths at the tangent directions of the nonlinear structural response. Therefore, convergence rates are faster when compared with the CO. As applications, composed structures were analysed with the developed formulations in linear elastic range. In addition, experimental fracture testes performed in concrete and wood specimens were also analysed. The confront of obtained results with the reference ones show that, the formulation was effective and accurate to evaluate the mechanical responses of composed structures in linear elastic range, and also to perform nonlinear quasi-brittle fracture tests.

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Data de Publicação
2015-04-15

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