Research On Fatigue Crack Growth Of 16MnR Steel With ANSYS

In recent years, with the larger and complexity of industrial equipments and the rigorous working condition, High-strength Low-alloy Steel has been used in pressure vessel continually, and the accidents of fatigue failure is increasing. Therefore, fatigue crack growth rate of 16MnR steel is simulated by both experiment and finite element method on ANSYS. These two methods have been compared and explained in the paper. The main points are as follows:First, the progress of research on fatigue crack propagation, damage mechanics and software of finite element method in the subject of fatigue and Fracture disciplines are introduced in detail.Secondly, based on large-scale general-purpose finite element software ANSYS, 16MnR steel CT specimens' fatigue crack growth model of the finite element method is programmed by APDL. The modeling processes can avoid recomposing program and the parameter of the model is able to input directly.Thirdly, in this paper fatigue crack growth is treated by damage method. Fatigue damage is assessed based on detailed stress and strain near the crack tip by using an incremental multi-axial fatigue criterion. The program programs by FORTRAN are for calculating fatigue crack growth rate.Finally, in order to draw the curves which plot the relation between the crack stress intensity factor amplitude and fatigue crack growth rate, the crack stress intensity factor amplitude should be calculated. The Calculation procedure for the crack stress intensity factor amplitude by VC is more convenient to calculating the parameterΔK.In practice, comparison of FE simulation and experiment results of 16MnR steel CT specimens, it shows that the current simulations of crack growth based on the perfectly plasticity model and fatigue damage criterion is accordance with the results of the experiments. Compared with the results of simulation on different stress rate condition, the average stress influences the fatigue crack growth rate. The finite element method for the crack growth rate has important practical significance and value in project.