Multi-Material Topology Optimization of Flexure Hinges Using Element Stacking Method

Traditional flexure hinges are designed by using a single material, and their performance is inadequate, compared to the ideal hinge. This paper presents a topology-optimization design method for multi-material flexure hinges based on the element stacking method. A topology optimization model for multi-material flexure hinges is constructed to find the optimal distribution of various materials, where the objective function is to maximize the compliance in the rotational direction, whilst minimizing the compliance in the axial direction. In order to ensure the rotation precision of the hinge, the position constraint of the rotation center is proposed. The gradient information of objective and constraint functions is derived by the adjoint method, and the method of moving asymptotes (MMA) is used to update the design variable. Several numerical examples are performed to verify the effectiveness of the proposed method, and the results show that the multi-material flexure hinge has a higher rotation ratio than the single-material flexure hinge.