Acoustic emission during fatigue crack penetration behavior of surface cracked plate

J. Ocean Eng. Technol. 1997;11(3):29-38.

표면균열재의 피로균열 관통거동에 따른 어코스틱에미션

남기우,김선진,오세규,이건찬,오정환,이주석

부경대학교 재료공학과,부경대학교 기계공학과,부경대학교 기계공학과,부경대학교 학연기계공학과,한국기계연구원,한국기계연구원

Keywords: Leak Before Break, Fatigue, Crack Penetration Behavior, Stress Intensity Factor, Acoustic Emission

핵심용어: 파단전누설, 피로, 균열관통거동, 응력확대계수, 음향방출

Abstract

Crack penetration behavior by fatigue crack propagation and measurements of AE before-and-after crack penetration were examined using SS41 steel plate. Experimental crack shape of SU type was in good agreement with calculated shape rather than S type. Crack propagation behavior on the front surface appears not to change markedly after penetration. However, crack growth on the back surface appears to accelerate as reported by author. As a crack propagates, AE occurred heavily just before penetration. Then, it decreases and crack is penetrating. A transition from plane strain to plane stress was observed by fractographic study. At this time, separation of fracture surface was shown which affects AE occurrence.