Numerical Simulation and Experiment on the Sliding Electrical Contact of the Solid Armature and Rails Interface

The solid armature of an electromagnetic rail launcher (EMRL) works in a time-varying multiphysical environment. To study the sliding electrical contact problem of the armature and rails interface (ARI), numerical simulation and sliding experiment are applied to describe the interfacial contact state. With the mechanical analysis of solid armature, the electrical contact model of an EMRL is built in this paper. The dynamic response state of the whole structural body and the contact state of the ARI are numerically simulated. The simulation results show that: 1) the high stress and little deformation occur in the armature throat, whereas the low stress and large deformation happen in the armature arm; 2) the contact pressure distributions of the ARI under the respective or joint action of the electromagnetic force and the pretightening force are all saddle shaped; and 3) the edge center of contact surface suffers the heaviest pressure under the joint effect, but the variation of the great mass of contact pressure along the direction of armature arm becomes gentler after superposition. The simulation results are verified by the worn states of the experimental armatures, and the changing process of the contact state is described by analyzing the distribution characteristic of the liquid melt remained on the rail surface.