Research on Delamination Failure of Insulator in Electromagnetic Rail Launcher

Abstract

The electromagnetic rail launcher (EMRL) G10 insulator is prone to delamination failure during launch, which affects the life of EMRL. In order to explore the reasons for the delamination failure of the insulator, the EMRL eddy current field calculation model is constructed firstly, and then the transient electromagnetic (EM) force distributions of the armature and the rail are calculated and verified by the combination of finite element and experiment. Finally, the EM force is used as the input, and combined with bolt pretightening force, friction force, and impact force, the multitype mechanical coupling solution is carried out. The simulation indicates that stress concentration occurs at the inner chamfer of the insulator end. The interlaminar shear stress exceeding the ultimate strength of the material and the fatigue damage caused by stress cyclic loading are the main reasons for the delamination failure of the insulator. The delamination crack is parallel to the direction of the glass fiber layer, and the interlaminar shear force peels off the upper fiber from the resin, forming a through-type delamination damage of the test prototype insulator. Optimizing the structure or material to improve the shear resistance of the insulator can prolong the life of the insulator.