Experimental and numerical characterization of fatigue crack propagation in high-speed railway wheel ER8 steel

Abstract

In this work, characteristics of fatigue crack growth in the Paris regime of the rail wheel steel grade ER8 were investigated. Experimental crack growth tests under different cyclic loads of a compact tension (CT) specimen and corresponding FE simulations were carried out. The extended FE method (XFEM) coupled with damage evolution based on the strain energy release rate or the Paris law was applied to describe the crack propagation mechanism in the tested CT samples. Hereby, the fatigue fracture model parameters were firstly determined from the experimental data. It was found that the predicted crack growth rates agreed well with the experimentally gathered results. Subsequently, fatigue crack propagations of the investigated wheel steel under varying load levels, load ratios and lengths of pre-crack were studied using the FE approach and the obtained crack growth characteristics were compared and discussed.