강구조 부재의 피로균열성장에 미치는 제인자에 관한 연구( II ) -표면잔류응력이 균열닫힘에 미치는 영향- = A Study on Parameters Affected the Fatigue Crack Growth in Steel Structure Members( II ) -The Effect of Surface Residual Stress for Crack Closure-

다국어 초록 (Multilingual Abstract)

To investigate the effect of fatigue crack growth due to the surface residual stress, it is measured the residual stress distribution by x-ray diffraction at the crack tip each constant crack growth in the notch specimens, and quantitively assessed the effect of crack closure caused to the distribution of compressive stress at the crack tip from evaluating crack openning stress using the finite element analysis. It is concluded that the degree of the residual stress distribution at the crack tip is decreased with increasing the crack length. From the fact that it is similar to the crack openning stress ratio, it is found that the compressive residual stress distribution and size is related to the crack closure effect and surface residual stress field with propagating crack in the notch specimens depends on the stress intensity factor range at the crack tip.