Analyzing Crack Signals in Cladding Layer Samples using Frequency Domain Analysis and Denoising

Compared to Figure 1(c), the cracked cladding layer sample in Figure 1(a), after being sprayed with color penetrant testing agent, shows numerous cracks that are almost spread throughout the sample. Comparing the waveform of signals in Figure 1(b) and (d), it can be observed that the crack signals exhibit significant mutations, and these mutated signals have much higher amplitudes than the normal signals. It can be understood that the waveform at the point of amplitude mutation represents the occurrence of a crack event. However, from the crack waveform in Figure 1(b), it can be seen that the crack signal contains a lot of noise interference, making some crack signals less prominent and unable to clearly distinguish whether they are signals of crack faults. Therefore, we need to perform frequency domain analysis and denoising processing on the original crack signals to facilitate subsequent waveform analysis.