Aiming at the problem of metal fatigue crack initiation and propagation life forecast, an unified a model was presented based on damage mechanics and finite element method, and the calculating program was established.The stiffness matrix was continuously calculated by introducing the additional loading method.The calculating program was designed in MATLAB and the calculation flow diagram was showed in this paper.Then through the calculation of a single cell, the changing process of equivalent stress was presented with the cell from undamaged state to completely damaged state and the reasons of the changes were analyzed. It was found that the crack initiation and propagation life was more than 80% of the total life. By finite element software ANSYS simulation, the crack initiation and propagation process of notched specimen were obtained. Finally, the results of theoretical calculation and the experimental data were basically identical, which verify the accuracy of this method. © 2017, Materials Review Magazine. All right reserved.
