Fatigue damage identification and life prediction method based on acoustic emission signal wavelet packet decomposition frequency band energy spectrum

The invention discloses a fatigue damage identification and life prediction method based on an acoustic emission signal wavelet packet decomposition frequency band energy spectrum. The method comprises the following steps: S10, acquiring an acoustic emission signal of a metal material or a welding structure under the action of a fatigue load in the whole process of a fatigue loading test; s20, determining an optimal wavelet basis of wavelet packet decomposition of fatigue damage identification; s30, performing multi-layer decomposition on the acoustic emission signal by using the optimal wavelet basis, and decomposing the acoustic emission signal into frequency sub-bands; s40, calculating the energy of a wavelet packet decomposition coefficient; s50, fitting to obtain a fatigue damage evolution equation; and S60, judging the fatigue life stage of the monitored object according to the fatigue damage evolution equation. According to the invention, sound signals of a metal material or a welding structure during