Evolutionary topology optimization of hinge-free compliant mechanisms

This paper develops a bi-directional evolutionary structural optimization (BESO) method for the design of hinge-free compliant mechanisms. A new objective function is proposed to maximize the desirable displacement and preclude the formation of hinges simultaneously. Sensitivity numbers are derived according to the variation of the objective function with respect to the design variables. Based on the resulting sensitivity numbers, the BESO procedure is established by gradually removing and adding elements until an optimal topology is achieved. Several 2D and 3D examples are given to demonstrate the effectiveness of the proposed BESO method for the design of various hinge-free compliant mechanisms.