基于R-SOBI的结构模态参数辨识方法

提出了一种基于稳健SOBI算法提取结构/系统的频率、阻尼比及模态振型的方法。运用该法提取系统/结构模态参数的步骤为:首先利用稳健SOBI的盲源分离方法采集的信号进行分离,然后将分离矩阵作为结构/系统的模态振型矩阵,最后再对各个分离后的单自由度信号提取频率、阻尼比参数。研究结果表明,提出的方法可以准确提取出结构/系统的模态参数,尤其是即使噪声环境下仍然能准确提取出系统的模态振型矩阵。

Modal parameter identification via robust second-order blind identification method

A robust second-order statistical method employed in blind source separation (BSS) was presented for use in modal parameter identification.Firstly, modal responses were estimated by the application of robust second-order blind identification(R-SOBI) technique on the measured vibration signals.And then, modal shapes were extracted from the de-mixing matrix above.Finally, frequency and damping ratios could be obtained from the modal responses using each single degree of freedom mode.Numerical results demonstrated that the proposed method provides a novel and robust approach to modal identification; especially, the modal shapes can be extracted exactly even in lower signal to noise ratio (SNR) case.