Simulations on Elastoplasticity of the Monolithic Aluminum Armature Under the Contact Force

Keeping good contact of the armature-rail interface (ARI) is essential for electromagnetic launch technology. To investigate the contact mechanism of ARI and improve the contact condition, the elastic-plastic deformation of the monolithic aluminum armature (MAA) under the contact force is analyzed. Contact force, contact area, and the distribution of contact pressure are calculated, and several kinds of armatures with different arm lengths are compared under the same conditions. The calculating loads include the pretightening force under the initial preload and the electromagnetic force from the pulse current. The simulation results show that both the contact force and the contact area under the plastic deformation are bigger than those under the elastic deformation, which is due to the higher spring-back force and displacement. A longer arm length can result in better flexibility and lower contact force. The effect of the electromagnetic force versus the contact force is increased with the arm length.