다축피로하에 응력 구배효과를 고려한 구름 접촉모델의 피로수명해석에 관한 연구

In this paper, a new formulation of gradient fatigue criteria is proposed in the context of multiaxial high-cycle fatigue (HCF). To predict exact fatigue life, it is necessary to calculate contact sress and subsurface stresses accurately. Contact stresses are obtained by contact analysis of a semi-infinite solid based on the use of influence functions and the subsurface stress field is obtained using rectangular patch solutions. Based on these stress values, a new gradient fatigue criteria which extended from classical ones with stress gradient terms introduced not only in the normal stress but also in the shear stress components is used. The results show fatigue life calculated and compared between considered gradient criteria and not considered gradient criteria.