Dislocation Model of Wheel–Rail Interaction with Locomotive Lateral Fluctuations

The model of interaction between the wheel of a locomotive and a rail based on taking into account the discrete structure of solid deformable bodies using the fundamental concept of metal lattice dislocations was developed. Under the action of applied normal and tangential forces, these dislocations can move and exit to the surface of the crystal or part, if, for example, the Mises yield criterion is fulfilled, which can be considered as a condition for the emergence of dislocations on the surface. The creep force is treated as the total force of destruction of the grippers between the groups of atoms of the wheel and the rail, and simultaneously, the occurring process of sliding the wheel along the rail—as a process of “collapse” of dislocations emerging on the contact surface, i.e., as a translational plastic flow (shear without deformation). It was shown that the creep force depends on the normal and tangential pressures of the wheel on the rail, as well as on a number of additional factors, such as an increase in the number of dislocations with an increase in the deformation rate of the contact zone and the coefficient of destruction of the oxide film. The satisfactory convergence of the results of calculations of lateral fluctuations of the locomotive obtained with the use of the proposed model and known experimental data is shown.