Abstract:Based on the high frequency electromagnetic interference(EMI) method, the damage patch structure is simulated and analyzed, and the influence of damage propagation on the EMI signal is studied in this paper. First,the threedimensional finite element model considered “piezoelectric patches (PZT)-main structure ” under six different damage cases is established by the ANSYS software. Then the conductance spectrum signal considering the damage depth of d and the distance s between the damage position and the piezoelectric patch is obtained by using the finite element model to analyze the powerharmonic response. Finally, the effect of the patch structural damage propagation on the conductance spectrum signal of the piezoelectric patch is analyzed with the vertical and horizontal comparison. The analysis results show that the resonant mode in the conductance spectrum of the piezoelectric patch can be accurately measured by using the threedimensional finite element model contained the fine damage, and then the local minor damage in the patch structure can be recognized very well. The validity of the existing impedance analysis method for the analysis of structures containing small damage is verified. When the damage location is closer to the piezoelectric patch, the more the signal peak of the conductance spectrum signals is shifted to the left, so the location of the fine structure damage can be determined by arranging the reasonable location of the piezoelectric patch.