Dynamic Stress Analysis Of Composite Track Of Electromagnetic Railgun

In the process of launching projectiles,the components of the electromagnetic railgun will be affected by many factors,such as electricity,force and heat,which will have a great impact on the launching accuracy of the system.Therefore,it is necessary to study the important components of the electromagnetic railgun in the process of launching projectiles.In recent years,although much progress has been researched of mechanical properties of electromagnetic railgun,it mainly focuses on single material rails.Moreover,due to the high current density and the phenomenon of current bypassing,the temperature value of the track and armature will increase and the distribution is not uniform.The material expansion and extrusion force between the track and armature caused by the temperature rise will aggravate the wear of the inner surface of the guide rail and greatly reduce the service life of the electromagnetic track gun.This paper focuses on the study of the transient current,temperature,stress and displacement distribution of the armature on the copper-based composite tracks at different time and different parts of the composite tracks when the railgun is electrified,which is different from the armature research at a specific time or position of the composite tracks.Based on the conformal mapping method,the distribution of current density on the track and armature is obtained.The temperature expression of composite rails is obtained according to the electromagnetic heat effect and heat conduction equation.The theoretical calculation method of current density distribution and temperature distribution in the track and armature during launching is given.The composite electromagnetic track is simplified into a mechanical model of double-deck beam.The stress of the contact part between the track and armature is analyzed by using the basic principle of half-plane.The stress of the contact part between the composite track and armature is calculated numerically by using the software of matlab.The multi-physical field coupling module in Comsol software is used to simulate the composite rails in the launching process,and the transient current,temperature,stress and displacement of the composite rails at different time points and different positions during its continuous operation are obtained.By comparing the temperature and displacement of steel and copper layers of composite rails at different time points,the practical performance of composite rails is better analyzed,and compared with the theoretical calculation results,the dynamic variables of composite rails have the same trend.