电枢运动引起电磁发射轨道的动态响应

DYNAMIC RESPONSE OF ELECTROMAGNETIC RAILGUN DUE TO ARMATURE MOVEMENT

电磁轨道发射装置中的电枢在受到推力向前移动的同时,轨道之间存在斥力.由于焦耳热效应的存在,电枢产生膨胀,同时对轨道产生一个挤压力,进而引起轨道的动态响应.本文将电磁发射装置的轨道简化为移动载荷作用下弹性基础上的简支梁.根据梁的振动理论,建立动力学微分方程,并应用数值分析方法,求得了电枢对轨道挤压作用下的轨道的位移动态响应;分析了电流强度、地基弹性系数、地基阻尼等参数对轨道位移的影响.其结果可为轨道结构设计提供必要的理论根据.

The repulsive forces exist between the two rails when the armature is thrusted forward along the rail. At the same time the armature expands due to Joule heat, which causes rail＇ s vibration. The electromagnetic rail was modeled as a simply supported beam of finite length sitting on an elastic foundation. According to the theory of vibration, the dynamic response of the rail was governed by a fourth-order differential equation with an extra term of elastic support subjected to armature＇ s thrust. Then the parameters, such as the current intensity, the elastic constant and damping of the elastic foundation, were analyzed. The theoretical basis of the design of rail was obtained from the analysis result.