Study on Acoustic Emission Damage Signal Denoising of 2D-C/SiC Composites

In the process of damage test of carbon fiber composites, the acoustic emission signal is affected by the measurement conditions and external environment, which contains a lot of noise problems. A denoising method based on wavelet threshold is proposed. Based on the analysis of the burst signal and continuous signal of carbon fiber composite, the wavelet analysis method is theoretically studied firstly. The selection criterion of wavelet base and the selection of wavelet decomposition layer are discussed theoretically, in order to solve the threshold of wavelet threshold denoising. A high-order non-conductible problem, a soft threshold function is proposed. Finally, the denoising experiments are carried out on the burst signal and the continuous signal respectively. The effects of different basis functions and different decomposition layers on the signal-to-noise ratio are compared. Finally, the optimal wavelet basis functions and the number of decomposition layers are obtained, which makes the denoising effect optimal.