Evolutionary Topology Optimization for compliant mechanism design

Claudia Marcela Pérez Madrid¹; Renato Pavanello¹; William Martins Vicente¹; Renato Picelli²

¹ Universidade Estadual de Campinas; ² Cardiff University

doi:10.20906/CPS/CON-2016-1640

Resumo

Compliant mechanisms are mechanical devices that achieve motion through elastic deformation. They represent a relatively new breed of lightweight structures and their use has been expanded given their advantages over the traditional rigid-body mechanisms. These improved characteristics include increased performance, high precision, low weight, lower cost, simplified manufacture, low part count, and ability to miniaturize. This paper develops a strategy for compliant mechanisms design using the bi-directional evolutionary topology optimization (BESO) method. This procedure requires choosing an objective function that handles motion and loading requirements simultaneously for a given set of input force and desired output displacements. The objective function maximizes the desirable displacement and reduces the formation of hinges at the same time. Sensitivity numbers are found by the objective function variation with respect to the design variables, to be later used in the BESO method to add and remove material until an optimal topology is achieved. Two examples are used to validate the implementation comparing the results with typical topologies found from previous works. Finally, the influence of some parameters used in the optimization process and the numerical implementation is analyzed.

Palavras-chave: Topology Optimization; Bi-directional evolutionary structural optimization; Compliant Mechanisms; Multi-criteria Optimization