Research on the Contact Characteristics of the Armature-Rail Considering the Wear Amount of the C-Shaped Solid Armature

The friction and wear characteristics of a C-shaped solid armature surface are the important factors affecting the electric contact of the armature-rail during electromagnetic rail launch. In order to judge whether the electrical contact state of the armature-rail is good and whether there is a transition during the launch process, this article proposes a theoretical analysis model of the armature-rail contact force considering the stiffness change of the armature arm after wear, and the nodal force and nodal temperature are extracted through finite element multiphysics coupling and mapped to the structural field with Johnson-Cook material damage failure for dynamic calculation of armature arm wear and armature-rail contact force. The simulation results show that the wear state of the armature arm, the change rule of armature wear mass, the velocity of armature after wear, and the change of armature-rail contact force after wear are consistent with the launch experimental phenomenon and the measured data, which verifies the accuracy of the finite element model for calculating the wear amount and armature-rail contact force. On this basis, the effects of different armature arm tail interference and different peak-to-average current waveforms on armature arm wear and armature-rail contact characteristics are considered. The simulation results show that the contact force curve of the armature-rail after considering wear is above the contact force curve required by the “10 N/kA” principle, and it can be considered that the armature-rail contact state is good. The calculation model of armature arm wear and armature-rail contact force established in this article can be used in the subsequent optimization design of C-shaped solid armature.