用测试的模态参数辩识结构参数

STRUCTURAL PARAMETER IDENTIFICATION USING TEST MODAL DATA

在本文中,以结构的正交特征方程等为约束条件,从求解带约束的拉格朗日函数极值入手,提出了一种用测试的模态参数辩识结构参数的方法.通过算例说明了本方法在模型中有不易测得的自由度或为聚缩模型时的应用.本文方法可用于复杂有限元模型的参数辩识.算例表明:本文方法有较大的误差修正范围,并且有良好的辩识精度.

A method which uses the measured modes and natural frequencies to/dentify structural parameters is formulated by selecting a measure of difference between analytical pa- rameters and those to be identified and using Lagrange Multipliers for minimizing changes in structural parameters to meet the constraint condition of modal orthogonality and the eigenval- ue equation.Examples are presented to illustrate how this method is applied to the models in which there are freedoms that can not be measured or that are reduced.The results of examples show that relatively large deviations between analytical natural frequencies and measused ones can be improved with this method,and that this method is effective and has a good accuracy.