基于谱约束下矩阵逼近的模型修正方法

A Model Updating Method Based on Matrix Approximation Theory with Spectrum Constraint

基于谱约束下的矩阵最佳逼近理论 ,提出一种新的以实验振动测试和参数辨识的数据为参考 ,进行有限元分析模型修正的方法。该方法以实验获得的不完备模态的谱点为约束 ,运用Bayes估计原理来处理试验结果误差带来的实验模态可信度问题 ,求取分析模型的最佳逼近结果 ,然后获得质量阵的最小修正模型。这一方法无需迭代 ,计算简洁 ,可以避免非完备模态空间中修正模型可能出现的“畸变”现象 。

A method for updating FE analytical model using the data from vibration test and parametric identification as a reference is put forward in this paper,based on the optimum approach theory of matric under the spectral constraints.The method makes use of the spectrum coming from the incomplete experimental modes as constraints,and solves the optimal approximation of FE model,so that the modified model with minimum change of mass is obtained.This method also pays repect to the affect from the experiment errors by using Baysian estimation principle.The method in this paper needs no iteration,keeps away from the cause of misshapen mode in modifying at the incomplete mode space,and shows the physical characteristics of the model and the clearness of computation.