C型电枢通过尾翼弹性变形为电磁发射提供枢轨壁面初始接触力，初始接触状态对电磁轨道发射全过程的滑动界面状态起决定作用，影响系统效率和轨道寿命。通过建立接触模型进行模拟计算和设计多组对比试验，研究了C型电枢作用下初始接触状态。考虑材料的安全变形控制范围，在电枢头部尺寸的微小变动和尾翼的不同设计尺寸下，分析了接触压强、接触区域(面积)、接触力的变化规律。提出了控制接触状态的关键参量——压入比，接触区域随压入比的增大从电枢尾部向头部移动，最大接触面积约占总接触表面的50%。讨论了良好电接触要求下最佳接触状态及其工程实现方法。

Sliding interface status during whole electromagnetic rail launch process depends on contact status after initial assembly in which initial contact force between armature and rails(A-R) is provided by trailing arm elastic deformation in the C-armature rail launcher, which influences launcher system efficiency and rail lifespan. This paper focuses on the contact status of initial C-armature assembly of rail launcher with constructing the contact model for simulating computation and designing many groups of experiments for contrast testing. Considering safe deformable limits of armature material, variation laws of contact pressure, contact region(area) and contact force are analyzed under conditions of small-range feasible heads and tail sizes. Interferential proportion is proposed as a contact status dependent key parameter. Contact region transformed from tail to head of trailing arm as interferential proportion increasing, maximum of contact area is about half of whole outer surface of trailing arm. Optimal contact status for favorable electric contact and engineering implement technique are also discussed.