Abstract
The railgun system is an electromechanical coupled system. The electromagnetic field may cause an essential change of the dynamic behaviors of the railgun system. Here, considering the changes of the electromagnetic force caused by the rail displacement, the electromechanical coupled dynamic equations for the rail are given. Using these equations, the natural frequencies of the railgun system and their changes along with the system parameters are investigated, the vibration modes of the railgun system are discussed, and the forced responses of the rail to the running electromagnetic force are analyzed. The results show that the moving electromagnetic force causes the changes of the natural frequencies for the railgun system. As the armature moves, the vibration modes of the rail are change as well. The electromechanical coupled effects change the forced responses of the rail to the running electromagnetic load. The effects are more obvious for larger armature distance and current, small distance between the two rails and stiffness of the elastic foundation. The results are useful for design and application of the railgun system.