Structural Optimization of Piezoelectric-Element Displacement Magnifying Mechanism(Mechanical Systems)

Abstract

Piezoelectric actuators using piezoelectric element displacement magnifying mechanism are applied to many kinds of mechanical devices. However, the design of displacement magnifying mechanism depends on experiences and skills of designers and takes much time for optimizing the structure. In this paper the method of structural optimization for displacement magnifying mechanism using FEM and sequential linear programming is proposed. First, the sensitivities of the typical functions, that is, the displacement of nodes, the force of output node, the stress of each elements and the static energy transfer efficiency are formulated. The dictionary of sequential linear programming is constructed out of these sensitivities. Then the optimization procedure which starts from a roughly designed fundamental structure of magnifying mechanism is constructed. Finally the method is applied to an example of punching device to confirm the robustness of the method and the propriety of the optimized structure from the mechanical engineering point of view.