단일과대 하중하의 균영성장시 소성영역의 크기와 균열 성장 모델에 대한 연구

초록

Load interaction effect due to the tensile overloading included in cyclic loading result in retardation in fatigue crack growth and it has significantly influence on the fatigue life of the structure. However, the crack retardation effect has not been considered exactly in the prediction of crack growth rate. Therefore in this paper crack growth tests for ESET specimens of engineering steel used in ships and ocean structures were conducted under constant-amplitude loading including a single tensile overload. The plastic zone size was determined from the strain distribution measured using ESPI system during crack growth retardation and the change of crack growth rate was carefully observed. Crack growth retardation model that was characterized by crack growth length and compared with test result.