Experimental and simulation investigation into residual stress for rail grinding with abrasive belt

To intuitively understand the residual stress state on the rail surface after belt grinding, the influences of grinding parameters on residual stress were investigated on a test bench. Portable residual stress instrument was used to acquire the residual stress along the central line on the ground rail surface. The residual stress along the grinding direction was tensile, the value ranges from 100 MPa to 300 MPa, while the one along the radial direction was compressive, the value ranges from 0 to -250 MPa. To investigate the mechanisms of the influencing factors during the forming process of residual stress, a 3D finite element model (FEM) of single-grain scratching based on thermo-mechanical coupling method was developed. Effects of contact surface friction, cutting depth and cutting speed on residual stress distribution in rail sub-layer were revealed, respectively, The mechanism was also analyzed. Finally, according to the experiment and simulation results, it is suggested that the grinding unit at the end of the grinding train should adopt open grinding. The abrasive belt requires small particle and strong self-sharpening. The grinding process should be suggested using low grinding pressure and low grinding speed with water for cooling and lubrication.