典型柔顺常力模块结构参数评估与有限元优化

Architecture parametric evaluation and FEA-based optimization of atypical flexure-based constant force module

为解决柔顺常力机构常力范围不足的问题,基于有限元方法分析结构参数对常力输出特性的影响,提出适应正负刚度组合常力机构的优化方法.首先,以一种Z型梁与双稳态梁并联的常力机构作为研究对象,通过对两种梁的力-位移特性进行分析,获得与机构常力特性相关的结构参数.然后,利用Workbench仿真,对比理论分析结果,得出未优化机构实现常力的输入位移区间为[1.2,2.5] mm,常力为18 N;并利用Matlab仿真,评估两种梁的主要结构参数对常力特性的影响.最终,运用有限元优化法求取结构参数组合的最优解,得出优化后机构实现常力的输入位移区间为[2.0,4.5] mm,常力为68.5 N.优化结果证明了该方法的有效性及可行性.

To solve the insufficient constant stroke and small constant force value of the flexure-based constant force mechanism,a FEA-based optimization based on architectural parameters was proposed in this paper.Originally,a constant force mechanism(CFM) combined with a Z-shaped beam and a bi-stable beam was regarded as the research object,and the main architectural parameters that affect the constant force were obtained with analysis of two beams.Furthermore,through simulation analysis and comparison with theoretical analysis,the constant stroke of the designed mechanism was [1.2,2.5] mm and constant force was 18 N.The parametric evaluation was conducted based on the relationship of force and displacement of the proposed mechanism by Matlab.Finally,the optimal solution of the architectural parameters combination were obtained by FEA-based optimization,with [2.0,4.5] mm constant stroke and 68.5 N constant force.The result showed the effectiveness and feasibility of the optimization method.