Abstract:

It is difficult to measure the input forces of some operating structures. Only the operating response data can be used to identify modal parameters. A frequency domain poly reference modal identification method under operational conditions was presented on the basis of the cross correlation function of measured responses to solve the only output problem. The proposed method in this paper was applied to an airplane model.

Key words: modal identification, operational conditions, cross-correlation function, cross-power spectraldensity, unknown excitation