Abstract:

：For the snapping control of bistable compliant structures, the inequality of the snapping driven forces for both the forward and backward strokes is a bottleneck problem limiting their engineering applications due to the complex switching of the driven mechanisms. According to the large deformation finite element method, the key factors affecting the nonlinear snap-through characteristic are theoretically analyzed. By introducing the snapping force, the stable position maintaining force and their ratio to represent the bistable characteristic, an effective design method is proposed to control the snapping threshold force through local cross-section optimization. By optimizing the design variables including the cross-section size, the number and their position of local elements in the two-step optimization model, a series of new configuration bistable structures are obtained with required bistable characteristics. The influences of both the thickness and the arrangement of the modified local-element on the snapping threshold and pathway are analyzed. Additionally, the snapping time and resonance frequency of the modified bistable structures have been calculated, which are almost the same with the original structure configuration. Considering the effects of the clamping position and the boundary condition on the results in the experiments, the simulation results are in good agreement with those by experiments, thus validating the effectiveness of the snapping control method.

Key words: bistable characteristic parameter, control, optimization, snap-through, bistability