Otimização topológica evolucionária de problemas com interação fluido-estrutura

The aim of this thesis is the development of a computational tool for the design of structures considering fluid-structure interaction using topology optimization. A methodology of structural topology optimization is proposed in association with finite element formulations of fluid-structure coupled problems. In this type of problems, the structure undergoes fluid loading, i.e., pressure and/or viscous loads. The difficulties in designing fluid loaded structures arise due to the variation of location, direction and magnitude of the loads when the structural shape and topology change along the optimization procedure. This turns out to be an additional difficulty for the traditional density-based topology optimization methods. In density-based methods, the pressure loaded surfaces are not explicitly defined due to the existence of intermediate density elements. In this thesis, it is suggested an alternative methodology to handle this type of design-dependent loads. With an extended bi-directional evolutionary structural optimization (BESO) method associated with different fluid-structure formulations, pressures and viscous loads can be modelled straightforwardly for any structural topology due to the discrete nature of the method. Thus, the problem is solved without any need for pressure load surfaces parametrization. The BESO methodology is extended considering the procedures of switching fluid-structure-void elements, new sensitivity analyses and constraints. Steady state problems are considered, including linear elasticity for the structural analysis and Laplace, Helmholtz and incompressible Navier-tokes flow equations for the fluid analysis. Constant and non constant loads are modelled. Several examples and applications are explored with the proposed methodology (AU)