基于动力学环境试验数据的模态参数识别

MODAL PARAMETER IDENTIFICATION OF EXPERIMENTAL DATA BASED ON DYNAMIC ENVIRONMENT

在被测系统做动力学环境试验的同时,将振动台台面和被测系统组成的新系统作为分析对象,以振动台给定的力谱(或加速度谱)作为激励,对被测系统进行模态参数的识别。基于结构的振动台环境试验数据,通过被测系统频域中的测点加速度测量值与台面加速度测量值之间的传递率函数,导出了一个被测系统的“广义频率响应函数”,并且通过对边界条件的进一步简化和假设,最终得到了系统的模态参数。仿真算例验证了本方法的有效性。

Modal paramters could be iddentified when the structure is tested under the dynamic shaker(environment).In the course of the identification,the new structure which includes the structure and the shaker's table-board is regarded as analysis object and the force spectrum(or acceleration response spectrum) given by the shaker is used for excitation.In the paper,a 'generalized frequency response function' of the structure is deduced through the(acceleration) transfer function formed by the ratio of the accelerations at measuring point to that on the base.And then the boundary conditions of the structure would be further simplified and supposed.So modal parameters coulk be attained.The method of modal parameters identification with acceleration transfer function under the dynamic environment is(validated) by the simulation operated in a random and a sine sweep mode.