Fatigue life estimation of the overloaded notched components

Abstract

This paper presents an estimation of fatigue life for notched components in the presence of residual stress due to overloading. The proposed method is based on the stress distribution analysis around the notch root. Despite many prediction methods, which are emphasizing stress value to define the hot spot, this method is more concerned with mean stress distribution and local stress ratio as controlling parameters of the fatigue mechanism. Mean and amplitude of effective stress play a vital role in the proposed method. This feature helps to take into account the effect of high plastic strains that appeared around the notch root due to the stress raisers. Some experiments were carried out in which specimens with different notch geometries underwent a wide range of loading conditions. Notches were designed to cover an extended range of the stress concentration factors from 2.06 to 6.93. Eventually, the experimental and predicted fatigue lives were compared to evaluate the model reliability. A good agreement between the results was observed. The method was found to be appropriate and conservative in predicting the fatigue life of both U- and V-notched components with low- and high-stress concentration factors.