Investigation into the use of wavelet transforms to analyse acoustic emission (AE) signals

Use of AE sensors for condition monitoring is increasing due to the enhanced signal to noise ratio achievable and hence potential for early detection of defects. However for a deterministic analysis the AE signals are not necessarily best served by the direct application of a Fast Fourier Transform (FFT). A possible alternative is the Wavelet Transform which decomposes the signal in a similar way to the FFT but uses a range of analysing sub component waveforms that more closely resemble the characteristics of the AE signals. This paper demonstrates an application of the Wavelet Transform to AE signals emitted from a bearing with seeded defects.