The Fatigue Behavior by Variety of Crack Length of Surface Cracked Plate with Stress Concentration Part

J. Ocean Eng. Technol. 1995;9(1):83-91.

응력집중부를 갖는 표면균열재의 균열길이 변화에 따른 피로거동

남기우,김선진

부산수산대학교 공과대학,부산수산대학교 공과대학

Keywords: Fatigue, Leak before break, Penetration behavior, Surface Crack, Crack length, Stress intensity factor, Stress Concentration

핵심용어: 피로, 파단전누설, 관통거동, 표면균열, 균열길이, 응력확대계수, 응력집중

Abstract

Surface defects in structural members are apt to be origins of fatigue cracks growth, which may cause serious failure of whole structures. Most structure has a part where stress concentrates such as welded joints, corner parts, etc. And then, analysis on crack growth and penetration from these defects, therefore, is one of the most important subjects for the reliability of LBB design. The present paper has performed an experimental and analysis on the fatigue crack propagation by variety in crack length of surface cracked plate with stress concentration part. The crack growth behavior can be explained quantitatively by using Newman-Raju equation and the stress partitioning method proposed by ASME B&P Code Sec. XI. The stress concentration factor $K_t$ has affected on the crack growth. The crack growth after penetration depends upon the initial front side crack length.