基于EEMD的薄板结构模态参数的识别

模态参数的识别在结构动力学分析中有着重要的作用。本文研究了一种采用时域响应信号,辨识薄板结构固有频率和阻尼比的方法。首先将信号进行EEMD分解,获得本征模函数(IFM),减弱模态混叠现象;然后采用Hilbert变换,利用单自由度自由响应信号的特点,识别出结构的模态参数。结合仿真和实验,结果表明该方法优于EMD和传统的半功率带宽法。

Identification of modal parameter is very important in the structural dynamic analysis. This paper discusses a time-do- main method to identify the natural frequency and damping ratio of thin plate. First, use the EEMD to decomposition the response sig- nal, and get the IFM component with less mode mixing. Then, according to the characteristic of the free response of one DOF system, use the Hilbert transform to identify the modal parameter. With the result of simulation and experiment, it clearly shows that this method is superior to the EMD and half-power bandwidth method.