Crack Signal Detection Using FFT and Wavelet Denoising

Transforming these two types of signals into frequency domain signals through Fast Fourier Transform (FFT), it can be seen from Figure 2 that there is a significant difference in frequency amplitudes between the crack signals and the normal signals. Amplifying the frequency waveform between 7500 to 8000 Hz, it can be observed that the frequency amplitude of the crack signals in this frequency range is greater than that of the normal signals. The crack signals exhibit multi-peak burst signals, with the frequency of crack faults being more prominent. In this paper, the wavelet threshold denoising method is used to denoise the crack signals.