一种直接求解的动态载荷识别方法

A dynamic load identification method based on direct solution

基于直接求解系统方程的位移响应,提出了一种时域内动态载荷的识别方法。该方法从中心差分格式的有限元离散形式出发,进行分块矩阵变换,将载荷识别问题转化为一个虚构系统方程的响应求解问题。通过数值算例,用两种不同形式的载荷检验了该方法的识别能力,分析了有无零相位滤波器对识别结果的影响。结果表明:所提出的载荷识别方法在位移响应数据含有噪声的情况下,能有效稳定地实现载荷识别;且计算简单快捷,抗噪能力强,不需进行模态分解,不存在模态截取等问题。

A novel dynamic load identification method in time domain is proposed based on direct solution to displacement response of dummy system.In the approach by using the central difference finite element formulation and partitioned matrixing,the dynamic load identification problem is changed into the corresponding direct problem about solution to displacement response of dummy system.So,the calculation is easy and rapid.The present method is applied to numerical examples,in which the identified ability is proved by using two different loads and the influence of identified precision between with and without zero-phase digital filter is analysed.The results indicate that the presented method is effective and robust for the load identification with the noise-contaminated response,its calculation is simple and fast,it has a strong anti-noise ability,with no need for any modal decomposition or modal cutoff.