Analysis of the Factors Influencing the Dynamic Response of Electromagnetic Rail Launcher

The dynamic response of an electromagnetic rail launcher (EMRL) has a direct influence on launch accuracy. With the Bernoulli-Euler beam located in the elastic support as an object of study, this paper presents an analytical model of the dynamic response of EMRL under the conditions of electromagnetic (EM) repulsive force and armature-and-rail contact force and obtains the analytical solution of the model. The redevelopment of the finite-element software makes it possible to perform a strong coupling transient simulation of the moving EM repulsive force, armature-and-rail contact force, moving thermal power, frictional thermal power, and the structural response in the dynamic launching process. Through the comparison of the results obtained by the analytical method, 2-D finite-element method (2-DFEM), and 3-D FEM (3-DFEM) for the dynamic response of the EMRL, the proposed model proves to be accurate and reliable. It is found that 3-DFEM can more accurately reflect the dynamic response process of the EMRL. On this basis, an analysis is made on the influence of the contact force, structural damping and heat on the dynamic response. The studies show that the contact force and the structural damping have little influence on the dynamic response under the condition of noncritical velocity, but have a great influence under the condition of critical velocity. However, the heat has a great effect on the dynamic response in both the conditions.