结构弹性支承刚度识别的广义逆特征值法

An Inverse Generalized Eigenvalue Method to Identify the Stiffness of Elastic-supports of a Structure

以带弹性支承的结构为对象,将结构刚度矩阵视为弹性支承刚度的线性函数,以广义逆特征值理论为基础,引入广义特征值导数,给出一种识别结构弹性支承刚度的方法.算例中,利用模态试验结果,根据前3阶实测固有频率,用Newton-Raphson法求解以支承刚度为参数的非线性方程组,求出弹性支承刚度,并分析模态试验结果误差对支承刚度识别的影响.误差分析表明,如果模态试验结果具有足够的精度,用本文方法能够准确地实现结构边界支承刚度识别.

In this paper,the author presents a method to identify the stiffness of elastic_supports of a structure basing on inverse generalized eigenvalue theory.The structure stiffness matrix is regarded as a linear function of the stiffness of elastic_supports,and the generalized eigenvalue derivative is also introduced.In the end of this paper,the example shows that using the modal test results the nonlinear equation sets,which contain parameters of the stiffness of supports,can be solved by Newton-Raphson's method,and the stiffness of elastic_supports can be identified.The effect of the error in the modal test results on the identification of stiffness of elastic_supports is also analyzed.The error analysis proves that this method can realize the exact identification of the structure boundary support stiffness if the modal test results are of enough accuracy.