A Study on the Wavelet Transform of Acoustic Emission Signals Generated from Fusion-Welded Butt Joints in Steel during Tensile Test and its Applications

맞대기 용접 이음재 인장시험에서 발생한 음향방출 신호의 웨이블릿 변환과 응용

  • 이장규 (인천대학교 기계공학과) ;
  • 윤종희 (인천대학교 기계공학과) ;
  • 우창기 (인천대학교 기계공학과) ;
  • 박성완 (인천전문대학 컴퓨터응용기계설계과) ;
  • 김봉각 (충청대학 항공기계설계학부) ;
  • 조대희 (인천대학교 교육대학원 기계교육)
  • Published : 2005.05.01

Abstract

This study was carried out fusion-welded butt joints in SWS 490A high strength steel subjected to tensile test that load-deflection curve. The windowed or short-time Fourier transform (WFT or SIFT) makes possible for the analysis of non-stationary or transient signals into a joint time-frequency domain and the wavelet transform (WT) is used to decompose the acoustic emission (AE) signal into various discrete series of sequences over different frequency bands. In this paper, for acoustic emission signal analysis to use a continuous wavelet transform, in which the Gabor wavelet base on a Gaussian window function is applied to the time-frequency domain. A wavelet transform is demonstrated and the plots are very powerful in the recognition of the acoustic emission features. As a result, the technique of acoustic emission is ideally suited to study variables which control time and stress dependent fracture or damage process in metallic materials.

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