International Journal of Engineering and Technology

In the present study, the effect of the overload together with the hold period of the overload to the fatigue life associating with the crack emerging from the notch root region is investigated because the region is vulnerable to the plastic deformation. The result of the study shows that the fatigue life is affected by the residual stress state in front of the notch root, and the state of the residual stress depends on the constant amplitude load condition following of the overload. The residual stress developing in the front of the notch root relates to the plastic strain in front of the notch root during the overload. Besides that, the hold period of the overload enhances the plastic strain developing in the front of the notch root. The higher plastic strain in front of the notch root reduces the compressive residual stress and increases the tensile residual stress. In addition, the compressive residual increases the fatigue life but the tensile one lowers the fatigue life. Therefore, the hold period of the overload may decrease the fatigue life.