Analysis Of The Wear Characteristics Of The Rail-armature Of Electromagnetic Railgun

During the launching of the electromagnetic railgun,the friction and wear caused by the relative movement of the rail-armature will cause the lack of contact surface material,result-ing in insufficient contact pressure,which will cause the arcing phenomenon of the contact surface and even transition.Moreover,with the development of electromagnetic railgun technology,the research of large-caliber launcher has been paid more attention.Therefore,through the simulation and analysis of the contact state,wear characteristics and different caliber railguns' wear,it is of practical significance to explore the wear mechanism and re-duce the wear degree of the contact surface,so as to improve the launching efficiency of the device,extend its service life and caliber design.The main work of this paper is as follows:The stress and electromagnetic field are coupled by using the finite element software,and the pre-tightening and Lorentz force are obtained.The contact state before and after the Lorentz force is loaded are compared,the influence of the interference and Lorentz force on the contact state of the rail-armature are analyzed.It is found that the pre-tightening force mainly provides the initial contact,and Lorentz force plays a leading role in the provision of the contact force.The maximum of contact pressure is distributed on both sides of the armature,and its position moves in the direction of head and tail as time goes on.Based on the Archard wear model,the contact state,wear volume and wear depth of the rail-armature are simulated,and the effects of the interference,acceleration and wear coef-ficient on the wear characteristics are analyzed.It is obtained that the contact pressure and area are positively related to the Lorentz force.Moreover,the influence of the interference on the contact state is obvious,and the optimal interference should be 0.2-0.25 mm.Try to improve the lubrication conditions of the rail-armature to reduce the degree of wear.Three kinds of caliber armature are designed based on Marshall's law,and the contact state and wear characteristics of different caliber railguns are analyzed.By comparing the launch efficiency,contact pressure distribution,wear volume,wear depth and wear volume ratio of the three caliber railguns,the large-caliber electromagnetic railgun should be given priority on the premise of the same launch speed.