中文摘要：

双稳态结构正反行程跳跃阈值不相等引起的驱动困难是制约其工程应用的瓶颈问题。基于大变形有限元理论分析了影响双稳态结构跳跃过程的关键因素,引入跳跃阈值力、稳态保持力以及双稳态特征系数（二者的比值）作为描述双稳态特征的指标,提出了基于局部单元截面构型优化的双稳态跳跃阈值控制方法,建立了具有特定跳跃力学特征的双稳态结构优化设计模型,以局部单元的截面尺寸、个数及位置为设计变量,采用分步优化的方法,得到了几类具有不同双稳态特征系数的余弦梁新构型,分析了变截面单元厚度及布置方式对跳跃阈值及路径的影响关系。数值仿真结果表明,局部截面构型改变前后双稳态结构的跳跃时间及振动频率变化不大。考虑试验加载位置与夹持条件对双稳态特征系数的影响,仿真与试验结果基本一致,验证了所提出的双稳态结构跳跃力控制方法的有效性。

英文摘要：

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.