Abstract:

The practical and effective expressions of stress strain constitutive relation and damage evolution for elastoplastic damage problems are proposed. For the intermediate and high cycle fatigue problems, a damage mechanics additional load finite element method is developed. By introducing the plastic additional loads, the influence of plasticity in the area of stress concentration on the fatigue life of the specimen is considered. The fatigue crack initiation lives for notched bar specimens of 30CrMnSiNi2A material, as well as the fatigue crack propagation, are calculated. The theoretical results by the present theory are in good agreement with the experimental results. It shows that the present method has important and practical values.

Key words: damage mechanics, finite element method, fatigue, axisymmetry, additional load method