Otimização topológica de estruturas com restrições de flambagem aplicada à manufatura aditiva

• Ano de defesa: 2020
• Autor(a) principal: Luiz Fernando Barbosa Carvalho
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; ENG - DEPARTAMENTO DE ENGENHARIA MECÂNICA; Programa de Pós-Graduação em Engenharia Mecanica; UFMG
• Palavras-chave em Português: Otimização topológica; Flambagem linear; Deposição de filamento fundido; Propriedades ortotrópicas; OpenMDAO; Engenharia mecânica; Otimização; Flambagem (Mecânica)
• Link de acesso: http://hdl.handle.net/1843/47269

As more extensive topology optimization problems considering stability analysis developed resulting in complex solutions, additive manufacturing processes were identified as alternatives to fabricate those solutions. Topology optimization problems by density methods are then here explored as applied to structures fabricated by the fused deposition modeling (FDM) method. The mechanical properties of those structures are highly dependent on the method printing parameters and those are treated in the optimization process. Two main printing parameters are considered: printing orientation and infill density. Different printing orientations were found to result in orthotropic properties on the resulting structures. The infill densities were related to the artificial densities variables used in the SIMP method (solid isotropic structure with penalization). With this comparison, a second category of optimization solutions was also proposed where the penalization function used in the SIMP method was replaced by a model of the mechanical properties as a function of a variable infill density parameter. Those solution make use of the capacity of the FDM method in fabricating structures composed of regions with different densities based on the infill. In order to explore the impact of the aforementioned properties, the proposed optimization problems consisted of structural compliance minimization under material volume and buckling constraints. The structure is modeled using the finite element method and buckling analysis was carried employing linear buckling analysis. This optimization model was implemented using the OpenMDAO modular paradigm. Two different case studies were considered for optimization, a column under compression and a short clamped plate, considering different orientation for the component fabricated. Solutions for both cases were obtained using classical SIMP penalization and also the variable infill density proposition. The solutions obtained showed that the distinct mechanical properties considered resulted in structures with different characteristics in its shape and consequently stiffness and stability.