基于频响函数模型修正影响因素的仿真

Critical Factors in Frequency Response Function Based Model Updating Using a Simulated Example

首先推导了基于频响函数模型修正的理论公式,在此基础上通过平面桁架模型修正的仿真算例,比较研究了基于频响函数模型修正方法具体实现过程中数据测量噪声、频率点选择以及频段选择等因素对修正结果的影响。研究表明,频率点的选择是基于频响函数模型修正的关键因素,合理的频率点选择既能够减小计算量,降低修正方程的条件数,同时还能够抑制测量噪声的影响;此外,提高实测数据的精度,增加修正频段的宽度也是改善模型修正效果的有效手段。

The basic theory of the frequency response function（FRF） based updating method was presented,and then the influences of the measured noise,the selection of frequency point and frequency band on the updating result were studied by using a simulated truss structure model.The conclusions show that：first,frequency selection is a key to the success of the updating,and appropriate selection of frequency point can decrease computational costs,improve the condition of the sensitivity matrix and resist the effect of measured noise;secondly,improving the accuracy of the measured data and increasing frequency band used in the updating are effective ways to get better updated model.