Topology optimization of compliant mechanisms including links, supports and material distribution

This paper proposes a novel topology optimization method integrating the layout of the supports, links and material distribution to design partially compliant mechanisms. The potential supports and links are distributed in the design domain in initialization, each with an active or inactive state. The nonlinear spring model is implemented for the unified modeling of potential supports and links. The mechanical properties of springs are associated with the states of supports and links. Within the traditional density-based framework, a new group of design variables representing the states of supports and links is introduced into the topology optimization model. For obtaining a physically realizable mechanism, the design variables representing the element density of the structure and the states of supports or links are uniformly penalized for avoiding intermediate values. Sensitivity analysis is conducted by implementing the adjoint equation method. The versatility and flexibility of the proposed method are demonstrated via numerical examples and the accuracy of the nonlinear spring model is verified by comparison of results.