基于灵敏度分析的结构动力模型修改

本文基于灵敏度分析和Taylor级数展开式提出了一种参数型结构模型修改方法。为了改进模型修改精度,本文从能量的观点出发引入一权矩阵,并给出模型修改方程的加权最小二乘解。数字算例表明本文方法具有很好的精度,并且在利用结构模态试验数据进行修改方面具有较好的适应性。

STRUCTURAL DYNAMIC MODEL UPDATING BASED ON SENSITIVITY ANALYSIS

A parameter-type method of updating structural models is presented based on a sensitivity analysis and Taylor series expansion. This method, choosing the practical design parameters as the variables to be updated, not only has clear engineering sense but also reduces the number of the variables significantly Generally, the number of the linear equations derived from Taylor series expansion is far larger than that of the unknown variables. In order to improve the precision of the equation solutions, this paper introduces a weighted matrix from the structural Kinetic and potential energy, and develops a weighted least squares solution for the equations based on the concept that the energy error between the updated model and the objective model is minimal. The numerical examples show that the method presented here can make the updated model in good agreement with the objective model. Especially, it is found from the examples that it is not necessary to use the model vectors containing all degrees of freedom of the structural analytical model. Therefore, this method has good suitability for the model updating by-using vibration test data in which the number of measured points for mode shapes is often much smaller than that of the analytical degrees of freedom.