Defect evaluations of weld zone in rails considering phase space-frequency demain

위상공간-주파수 영역을 고려한 레일 용접부의 결함 평가

  • 윤인식 (대한검사기술(주)) ;
  • 권성태 (한국철도연구원 차량연구) ;
  • 장영권 (생산기술연구원 산업기술시험평가연구) ;
  • 정우현 (강원산업(주)기술) ;
  • 이찬석 (한진중공업 연구개발부)
  • Published : 1999.06.01

Abstract

This study proposes the analysis and evaluation method of time series ultrasonic signal using the phase space-frequency domain. Features extracted from time series signal analyze quantitatively characteristics of weld defects. For this purpose, analysis objectives in this study are features of time domain and frequency domain. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics resulting from distance shifts such as parts of head and flange even though the types of defects are identified. These differences in characteristics of weld defects enables the evaluation of unique characteristics of defects in the weld zone. In quantitative fractal feature extraction, feature values of 3.848 in the case of part of head(crack) and 4.102 in the case of part of web(side hole) and 3.711 in the case of part of flange(crack) were proposed on the basis of fractal dimension. Proposed phase space-frequency domain method in this study can integrity evaluation for defect signals of rail weld zone such as side hole and crack.