A Rapid Evaluation Method of Fatigue Life for Structures Based on Notch Geometry Parameters

An analysis method based on notch geometry parameters is presented to quickly estimate the fatigue life of notched parts by taking the stress gradient effect at the notch root into account. This method adopts the notch geometry parameters to calculate the stress gradient by assuming that the principal stress decreases linearly at the notch root, and then combines the point method(PM) of the theory of critical distance (TCD) to obtain the fatigue damage parameter. The fatigue damage parameter is the function of the absolute stress gradient \(\overline{\chi }\) and stress concentration factor KT. Compared with traditional methods, this method does not require refined finite element analysis of the area near the notch. The fatigue test data of four different notches of two kinds of materials are collected to verify the method. The results show that the method proposed can accurately predict the fatigue life of notched components, and all the predicted lives fall within the 3-time error band.