Multi-objective topology optimization of multiple materials compliant mechanisms based on parallel strategy

Abstract

Compared to single-material mechanisms, multi-material mechanisms design enables designers to fully exploit the advantages of different materials and achieve more design freedom in force, motion, and energy transduction. A new multiple objective topology optimization for multiple materials compliant mechanisms is presented. Central to the method is a parallel penalization that works by decomposing an overall multi-material optimization into a series of single material optimization and coordinating the sub-optimization so that the joint solution is optimal for the overall system. A new material and objective corresponding relationship is proposed to ensure that each sub-problem contains only one objective. The single-material optimization sub-problems are accomplished by the solid Isotropic material with penalization (SIMP) method. The overall procedure has its unique benefits: it is simple in concept and practice; it is flexible to handle an arbitrary number of candidate materials; it can avoid fragile topologies and is therefore advantageous for manufacturing. Several numerical examples are given to illustrate the effectiveness of the proposed method. The results show that the proposed method is more effective in the design of specific materials.