Abstract: The local stress-strain approach has been widely used to predict the low-cycle fatigue life for notched members. The life prediction using this approach requires the local stress and strain at a notch root. The elastic-plastic finite element method can be used to obtain the local stress and strain.But it requires complex computer program. Neuber's rule is a simple and commonly used method. Some papers have shown that Neuber'rule is generally more conservative than the corresponding finite element analysis. In this paper the energy method for calculating the local stress and strain at a notch root is presented. Based on the deformation theory of plasticity, it has been generalized to the plane strain condition. Numerical examples show that the fatigue life predicted by the local stress strain using the energy method agrees favourably with the experimental results.

Key words: energy method, low cycle fatigue, life prediction