Based On The The Hhsa Method Of Structural System Identification And Damage Diagnosis

Recently, application of an innovative and efficient data analysis techniques in system identification and damage detection of civil structures is receiving much attention. Based on the Hilbert-Huang spectral analysis, a method is used to identify multi-degree-of-freedom systems using measured vibration time histories. In this method, the measured response data are first decomposed into modal responses using empirical mode decomposition(EMD) approach with intermittency criteria. Then , the Hilbert transform is applied to each modal response to obtain the instantaneous amplitude and phase angle time histories. A linear least-square fit procedure is proposed to identify the natural frequency, damping ratios, physical mass, damping and stiffness matrices from instantaneous amplitude and phase angle for each modal response. Numerical simulation and experiment are illustrated to demonstrate the validation and accuracy of this method for system identification and damage detection...