Determinação da resistência mecânica de materiais porosos plasticamente ortotrópicos via homogeneização computacional

Detalhes bibliográficos
Ano de defesa: 2023
Autor(a) principal: Galvão, Marcio Nilo Teodoro
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de Santa Maria
Brasil
Engenharia Mecânica
UFSM
Programa de Pós-Graduação em Engenharia Mecânica
Centro de Tecnologia
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://repositorio.ufsm.br/handle/1/29250
Resumo: This work evaluates the strength of porous elastoplastic materials with orthotropic matrix, which is assumed to be insensitive to both the mean stress and the strain rate, via computational homogenization procedure. The simulations are carried out on cubic elementary cells, employing the finite element method under small strains. Each elementary cell represents an agregate composed of a non-hardening elastoplastic matrix with symmetrically distributed voids (spherical or cylindrical), considering distinct porosity and matrix anisotopy levels. From the numerical analysis, effective yield surfaces are build imposing displacement-based boundary conditions while keeping the macroscopic stress triaxiality constant throughout the deformation process. After reaching an asymptotic macroscopic stress state, the macroscopic stress components are calculated from standard volume average from their microscopic counterpart. The numerical results are compared with analytical solutions (upper, quasi-lower and lower limits) available in the literature and one developed in the context of this work to materials with Hill matrix and cylindrical voids. Furthermore, aiming at reducing the difference between the numerical and theoretical results, which is due to difference regarding the geometry of both numerical and theoretical eleementary cells, heuristic modifications are proposed to the analytical models. Therefore, it is expected that this work contributes to the understanding regarding the mechanical behavior of porous material with plasticaly anisotropic matrix, which for instance, is the case of materials and structures produced by additive manufacturing.