Dynamic Response and Armature Critical Velocity Studies in an Electromagnetic Railgun

A model is developed to investigate the dynamic response of an electromagnetic railgun structure, induced by a moving magnetic pressure during launch of projectiles. When railgun armature velocity achieves critical velocity, resonance in railgun can occur and cause high amplitude stress and strain in armatures passage and causes life decreasing and damaging in rails. Critical velocity can be considered as one of the railgun dynamic design parameters. In this study, governing equations for rails under dynamic loading conditions has been investigated. Armature critical velocity according to design parameters has also been studied. The results show that dynamic response of the EM barrel becomes critical for increased projectile velocity and lightweight barrel designs. Also, the results of numerical simulation of the bore deformation are presented in this paper under applied loads. The algorithm is used to study the dynamics of tensile stresses near the electrode surface. Accordingly, the model that accounts for projectile velocity and gun construction can be used to guide and improve barrel design.