Damage and Failure Analysis of Insulation Structure of Electromagnetic Coil Launcher in Multiphysics Environment

To analyze the physical field distribution during the electromagnetic coil propulsion process and the possible reasons for the failure of the coil insulation structure, a numerical model of electromagnetic coil launcher (EMCL) in the multiphysical environment was established for calculation, and the damage characteristics of the driving structure after the electromagnetic emission test were analyzed. The results showed that the middle area in the
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-direction and inner walls of the skeleton experienced relatively high stress and strain amplitudes. The main cause of insulation structure failure is the generation of structural cracks on the inner wall and interphase partition. As these cracks develop, discharge arcs may occur between adjacent coils, as well as between coils and armature, which may lead to material aging and crack propagation, thereby forming a vicious cycle of insulation structure degradation. However, the heat accumulation during the commonly considered pulse excitation process is not sufficient to cause material carbonization, so the main reasons for insulation structure failure are considered to be stress overload and plastic strain accumulation. This article provides meaningful reference for the subsequent optimization of electromagnetic coil propulsion devices.