一种推广的互功率谱模态识别法及其在SHM问题中的应用

Modal identification based on cross power spectra density and its application to ASCE SHM benchmark

详细推导了多自由度结构多测点加速度响应的互功率谱模态矩阵展开式。进而给出了未知激励条件下基于各测点加速度响应互功率谱的频域多参考点模态识别法,同文献[1]相比,该法适用于更广范围的激励条件。在频域平均法的辅助下,对ASCESHMBenchmark问题的解析模型仿真加速度响应数据进行识别,结果表明该法有较好的识别精度,是一个有望应用于在线监测环境下的模态识别算法。

The modal matrix expansion of the cross power spectra of the multi-measurement acceleration response in the multi-DOF structure is derived in detail. A frequency domain multi-reference modal identification method based on the cross power spectra of the acceleration response under the unknown excitation conditions is given in this paper. In comparison with the reference\, it is applicable for a more extensive scope of excitation condition. By applying it to the ASCE SHM benchmark problem, aided by the frequency average method, a good identification precision may be attained by this method. It is a hopeful modal identification method for the purpose of online monitoring condition.