Experimental Research and Fatigue Life Prediction of Ultra-High-Strength Steel Aermet100

Abstract

This study concentrates on the fatigue performance of ultra-high-strength steel Aermet100 under different loading rates. The standard specimen measured the static mechanical properties of Aermet100 steel, based on which the basic mechanical properties and fracture characteristics of the sample before and after necking was obtained. To take the strain rate effect into account, this study uses the dynamic constitutive model Johnson-Cook. The equation parameters are fitted through dynamic mechanical tests and quasi-static tests. This model is input into ABAQUS user-defined program afterward. Referring to the work done above, along with the extended finite element method (XFEM), this study establishes the dynamic fracture finite element model of the Aermet100 steel specimen on the basis of the continuous damage mechanics. Five groups of specimen fatigue tests were carried out in the laboratory. Simulation results show the feasibility and accuracy of the integrated XFEM model with the same loading and boundary conditions. The experimental data and simulation results prove that, in the loading time range of 0.0001 ~ 1s, the life cycles increase as the loading rate increases. It is worth mentioning that when the loading time is in the order of 0.0001s, the life changes significantly.