Research on Fatigue Crack Propagation of 304 Austenitic Stainless Steel Based on XFEM and CZM

The fatigue crack propagation of 304 austenitic stainless steel was studied both by experiments and numerical simulations. Two methods were applied to simulate the crack propagation: the extended finite element method (XFEM) and the cohesive zone model (CZM). Based on the XFEM, the direct cyclic solver was used to simulate the fatigue crack propagation. Based on the CZM, the VUMAT subroutine was used to describe the crack tip constitutive equation during fatigue crack propagation, and the mechanical properties of the crack tip were simulated. The effects of different frequency,f, and stress ratio,R, on the fatigue crack growth life were studied by XFEM and CZM separately and compared with the experimental results. Results show that the crack propagation path simulated by the XFEM agrees well with the experimental result, but the deviation of the fatigue life between the simulated results and the experimental results is large. The CZM model can predict the crack propagation life very well in comparison with the experimental data, but it has certain limitations because the crack propagation path is preset.