Multi-field coupled analysis of the launch coil in active EM armor

Active electromagnetic (EM) armor is a new kind of active defense system, which consists of advanced detector, control system, high pulsed-power supply and EM launcher. Electric energy provided by the high pulsed-power supply can be transformed into kinetic energy of the interception projectile with EM launcher. Hit by interception projectiles, the invading object can be destroyed totally or deviate from its trajectory. Launch coil is a key component of the EM launcher and it should be destroyed because of its strength shortage if the current load exceeds some value. In this paper, the structure and working principle of the EM launcher are introduced. 3-D finite element model of the EM launcher is established. With finite element analysis (FEA) codes, multi-field coupled analysis (EM-thermal-structural analysis) of the launch coil is accomplished when the load is applied. The distribution of temperature, deformation and stress of the launch coil vs. time are achieved. Influence of the loads of the coil on its temperature and strength are also analyzed. The results indicate that the maximal temperature, deformation and stress appear at the center position of the launch coil and this part is easy to be destroyed. This appearance is well-matched with the experimental result.