Analysis of Rail Dynamic Deformation During Electromagnetic Launch

Abstract

During the process of launching electromagnetic railguns, armatures move along rails under thrust when current pass rails; in the meantime, certain deformation will take place on the rails, which armatures pass as they are under the action of the Lorentz force and armature pressure. Since the external support structure of rail gun provides flexible support for the rails, they can be simplified into elastic foundation beams. Based on the theories of electromagnetic field and heat transfer, the forces on rails can be derived. The dynamic response equation is developed according to the theory of elastic mechanics to evaluate the rail deflection during the launch, and thus to obtain the dynamic deformation of the rails. Based on the specific parameters and characteristics of launchers, a deflection calculation formula is derived. Related experimental data obtained are substituted into the formula to calculate the rail deflection of the rails during the process of launch. By doing so, the dynamic response of the rails under moving load is captured. A laser vibrometer is utilized to measure the deformation of rails during the process of launch. The measured data of rail deformation at the measuring points are obtained and compared with theoretical calculation results.