随机激励下载荷谱识别

Loading identification of structures subjected to random excitations

采用逆虚拟激励法进行载荷识别,识别结构所受平稳随机激励的功率谱密度,在钢悬臂梁和有机玻璃框架上进行了多次试验,识别的载荷与实际值符合得较好.同时研究了相干和不相干随机激励两种情况下载荷识别结果的异同,通过实测数据讨论了不同噪音对识别结果的影响.此方法的优点在于识别未知载荷的准确性、计算的高效性和对频响函数病态的克服能力.

The inverse pseudo excitation method is utilized to identify the power spectral density of loadings for structures subjected to stationary random excitations. Experiments were conducted on a steel cantilever beam and a plastic glass frame, and the identified loadings agreed well with the actual excitations. Furthermore, measured experimental data are used to investigate the effects of correlated and uncorrelated excitations, noises of the responses on the precision of loading identification. Advantages of this method include its accuracy of loading identification, computational efficiency and its ability to overcome the ill conditioning of frequency response function.