Spectral analysis for crack detection during TIG welding using acoustic emission techniques

Abstract

In this study, the tungsten inert gas (TIG) welding process was applied to high-carbon steel plates in order to simulate hot cracking in welds. A customised acoustic emission (AE) system was used to capture the AE waveforms generated during welding and cooling of the sample plates. The AE signals were analysed using fast Fourier transform (FFT) and short-time Fourier transform (STFT) algorithms. Comparison of the features arising from different sources observed in the frequency spectra of the acquired AE signals was carried out. The results demonstrate the possibility of applying the AE technique for monitoring and detecting signals generated from cracking activities using frequency domain analysis.