设计灵敏度分析的迭代模态法

Interative Modal Method for Sensitivity Analysis of Design Parameters

在结构动态有限元数学模型修正、结构动力学修改以及结构动态设计中，灵敏度分析是十分重要的一环，往往也是主要计算工作量所在。如何在保证精确度前提下减少灵敏度分析工作量和计算时间，具有重要意义．本文提出的迭代模态法，可以大大提高特征向量对设计参数导数（模态灵敏度）的计算效率。本文还从理论上证明经典模态法和修改模态法只是迭代模态法的特殊情况。文中还给出了ＦＯＲＫ，３Ｄ－ＦＲＡＭＥ两种结构为实例的计算机仿真，并与已有两种模态方法进行比较。理论分析与计算机仿真表明，本方法不仅能充分保证特征向量灵敏度分析的精度，而且大大提高了计算速度．

Derivatives of vibration mode shapes with respect to design parameters are very important in the structural dynamic design,FE model refining and.structure updating. As its calculation is very time consuming,so it is important to reduce calculation work and computation time within a given accuracy. Using iterative modal method introduced in this paper,efficiency can be greately improved in the calculation of sensitivity. In this paper theory certification is given that both classical modal method and modified modal method are special cases of the iterative modal methods. All three modal methods are implemented in a FE program and applied on two computer simulation examples: FORK and 3DFRAME. It is shown that through theory analysis and computer simulation that using iterative modal method in sensitivity analysis can guarantee calculation accuracy and greatly raise computation efficiency.