响应信号, 模态参数, 盲源分离, 锤击信号, 信噪比

A method of identifying the structure"s modal parameters by second order non-stationary source separation(SONS) arithmetic was proposed only using structure"s vibration response signals.On the basis of introducing the process of SONS algorithm and the steps of using BSS method to identify modal parameters,an experiment was carried out using the hammering signals of simply supported beam, and the response signals with noise were analyzed. The experiment demonstrates that the structure"s low order mode shape, natural frequency and damping ratio are picked

up by SONS method accurately.The SONS algorithm has good noise immunity, and its separation results are better and more steady than SOBI(second order blind identification) algorithm.Aiming at the phenomenon where high order modal parameters can not be identified very well using direct BSS method, a method of doing BSS after signal filtering was proposed and high order natural frequency was identified by this method successfully.

response signal, modal parameter, blind source separation(BSS), hammering signal, signal-noise ratio(SNR)