Stable Fatigue Crack Propagation of 16MnR Steel

Abstract

A research on the stable fatigue crack propagation of 16MnR steel is investigated systematically in this paper. First, control experiments of 16MnR with compact tension specimen is conducted to study the effect of R-ratios, specimen thickness and notch sizes. The experiments show that the fatigue crack growth (FCG) rate in stable propagation was insensitive to these factors. Then, the stress intensity factor (SIF) is computed and compared by displacement interpolation method, J integral and interaction integral method respectively. The simulation shows that optimization on the mesh density and the angle of singular element improved the computational efficiency and accuracy of SIF and the interaction integral method has an obvious advantage on stability. Finally, the FCG rate is modeled by the Jiang fatigue damage criterion and the extended finite element method (XFEM) respectively. The simulation results of FCG rate are in line with experiments data and indicate that XFEM method is more accurate than Jiang fatigue damage method.

Keywords

16MnR / crack propagation / stress intensity factors / fatigue damage / extended finite element method