Modal Parameter Identification of Mechanical System Based on EMD Method

The vibration signal of the mechanical system contains a wealth of status information, which has practical significance that cannot be ignored. Aiming at the problem of modal parameter identification of mechanical system, a modal parameter identification method based on empirical mode decomposition (EMD) is proposed. This method firstly decomposes the mechanical system under excitation vibration by EMD and then determines the intrinsic mode function(IMF) and correlation corresponding to each mode of the system, and performs Hilbert transform on each IMF to obtain the instantaneous frequency. Meanwhile, the method is applied to the residual stress detection of large-scale welded components, and good results are obtained.