基于改进遗传算法主动柔性结构压电元件位置优化

基于改进的遗传算法提出了一种解决多压电片布置在柔性结构上以实现振动主动控制的有效方法.本文采用D优化设计准则,即把Fisher信息矩阵行列式最大值作为目标函数的一种优化方法.通过对结构模态振型和动力特性的研究,使用一种简单的方法将所选择的低阶模态振型转化为归一化形式,最后通过结构模态振型可确定压电片最优位置.为了达到更好的振动控制效果,压电片布置在结构模态应变最大位置处.当在结构不同位置上布置压电片时,结构各阶模态振型也将随之发生不同程度的变化.本文建立了ANSYS软件和遗传算法的接口来实现对结构的模态重分析,从而提取各阶模态振型.

Application of improved genetic algorithms for pizoelectric element placement of active flexible structures

In order to suppress undesired vibration effectively,the paper proposed an optimal method based on the improved genetic algorithms and D-optimal design principle.This principle can be simplified to determine the probable placement of piezoelectric elements only based on mode shapes of structure.Through the study of modal shapes and dynamic characteristics of structure,a simplified method is employed to convert low order mode shapes selected from all structural modes into normalization.Generally,piezoelectric elements should be placed on the surfaces where modal strain is maximal so as to achieve the best control efficiency.But when piezoelectric elements are patched on the surfaces,the structures have different mode shapes.Therefore,the paper realizes the interface between ANSYS software and genetic algorithms.In this way,ANSYS software can iteratively analyze flexible structure boned piezoelectric elements and provide all mode shapes for the optimization,and genetic algorithms optimize the placement of piezoelectric elements repeatedly until finding the optimal locations.At last,a case shows the efficiency and feasible of the method.