A Study on the Microscopic Model for Fatigue Crack Closure Behavior

J. Ocean Eng. Technol. 1990;4(1):81-86.

O Se-Uk,Gang Sang-Hun

피로균열 개폐구거동의 미시적 모델에 관한 연구

오세욱,강상훈

동아대학교 기계공학과,동아대학교 기계공학과

Keywords: Fatigue Crack Closure, Stress Ratio, Effective Stress Intensity, Residual Displacement, Crack Tip Opening Displacement

핵심용어: 피로귀열폐구, 응력비, 유효응력확대계수, 잔류변립, 귀열선단개구변립

Abstract

Fatigue crack closure levels based on the behavior of residual displacements on crack surfaces, are determined analytically according to the microscopic crack closure mechanisms, i.e., whether the first contact of crack surfaces takes place at the very crack tip or on the surfaces near the tip. The comparative analysis on the two models is carried out empirically by the constant amplitude fatigue tests on 2024-T3 aluminum alloy plate, and it shows that under negative stress ratio, the case of the first contact at crack tip gives better agreement with the experimental results than the other.