基于克里金模型的压电位移放大机构优化设计

Design and Optimization of a Piezoelectric-Driven Displacement Amplification Mechanism

摘要:

设计了一种以叠层型压电陶瓷驱动、基于三角形放大原理的压电位移放大机构，并采用有限元方法对其静、动态性能进行仿真分析。为优化机构性能，以位移放大比和结构刚度最大化为目标，考虑尺寸参数对性能的影响，利用最优拉丁超立方生成设计空间样本点并进行有限元计算。基于计算结果和克里金算法建立优化目标的代理模型，使用非支配排序遗传算法获得最优解集。优化结果表明，位移放大比较初步设计时提升了 17. 4%，刚度提升了 5. 3%。根据优化尺寸加工了实验样机并进行测试，测得所设计放大机构的位移放大比为 8. 49，与仿真值相近。

Abstract:

A piezoelectric displacement amplification mechanism， driven by stacked piezoelectric ceramics and based on the triangular amplification principle， is designed. Finite element analysis is employed to simulate the static and dynamic performance of the mechanism. To optimize its performance， the displacement amplification ratio and structural stiffness are maximized as objectives， considering the influence of dimensional parameters on performance. The optimal Latin hypercube sampling method is used to generate sample points in the design space， followed by finite element computation. Based on the computational results， a surrogate model of the optimization objectives is constructed using the Kriging method， and the non-dominated sorting genetic algorithm （NSGA） is applied to obtain the optimal solution set. Simulation results demonstrate that the displacement amplification ratio improved by 17. 4% and stiffness increased by 5. 3% compared to the initial design. An experimental prototype is fabricated based on the optimized dimensions， and test results show that the displacement amplification ratio of the designed amplification mechanism is 8. 49， which closely matches the ratio obtained from the simulation.