Structural Design of Armature With Interference at Both Ends and Analysis of Its Launching Performance

Monolithic U-type armature is one of the most important armatures in electromagnetic railgun. First, based on the traditional U-shaped armature, this article proposes a new structural design of the armature with interference at both ends. In addition, based on the calculation results of the interference fit module, a railgun multiphysical field coupling model is established. Second, through the interference fit module, the armature's equivalent stress and a series of contact characteristics variables of the new armature with different structural parameters are calculated'C and the variation laws of the initial mechanical properties with different structural parameters are acquired. Finally, according to the current transport requirement of 200 kA, short-arm armature 1 and long-arm armature 2 are designed according to the traditional U-shaped armature structure design scheme, and the new armature 3 is designed according to the novel armature structure design scheme. Through the multiphysical field coupling model, the influence of the temperature and thermal stress on the launching performance of the three armatures is obtained. The calculation results show that the thermal stress and temperature will cause a sharp increase in the plastic volume and melting volume of the three armatures and eventually reduce the mechanical properties of the armatures. In addition, thermal stress will cause the contact position of the traditional armatures to move forward, affecting the stability of electromagnetic launching. However, the new armature can always maintain the contact between both ends of the tail and the rail, greatly reducing the influence of thermal stress on the armature launching performance.