基于接触特性的四轨电磁发射器电枢结构分析

Armature Structure Analysis of Four-rail Electromagnetic Launcher Based on Contact Characteristics

为深入探究四轨电磁发射器双曲电枢结构对接触特性的影响,本文利用有限元分析方法,分别从电枢过盈量、电枢臂末端厚度、电枢喉部厚度等关键结构参数入手,对通电接触特性进行多物理场耦合仿真。针对过盈量的设计,提出一种迭代仿真方法,通过循环仿真对接触压力进行求解,使其与期望接触压力进行比较,从而达到不断逼近最优过盈量的目的;针对电枢臂末端和电枢喉部的研究,充分考虑摩擦力、洛伦兹力以及初始过盈等因素,采用电磁-结构场耦合仿真方法对通电接触特性进行求解。结果表明:电枢喉部主要用于承受大电流以及强磁场所带来的应力;电枢臂末端主要用于传导大电流,而电枢头部对通电接触特性影响较小。在一定范围内增大电枢臂末端厚度可改善电接触性能,但电枢臂外扩现象加剧,进而加重枢轨间的磨损和烧蚀;在一定范围内增大电枢喉部厚度不仅可以改善枢轨间的电接触性能,同时使电枢结构更加稳定。

In order to further explore the influence of the hyperbolic armature structure of four-rail electromagnetic transmitter on contact characteristics,the finite element method was adopted to simulate the energized contact characteristics from the key structural parameters such as the armature interference,the thickness of the end of the armature arm and the thickness of the armature throat.To determine the interference,an iterative simulation method was proposed.The optimal interference was continuously approached by calculating the contact pressure through cyclic simulation and comparing with the expected pressure.Aiming at the research of armature arm end and armature throat,the factors such as friction,Lorentz force and initial interference was considered,the electromagnetic-structural coupling simulation method was used to solve the energized contact characteristics.The results show that the armature throat is designed for bearing the stress caused by high current and strong magnetic field.The end of the armature arm is mainly used to conduct large current,while the armature head has little effect on the energized contact characteristics.In a certain range,increasing the thickness of the end of the armature arm can improve the electrical contact performance,but the outward expansion of the armature arm intensifies,which aggravates the wear and ablation between the pivot rails.Increasing the thickness of armature throat in a certain range can not only improve the electrical contact performance between armature and rails,but also make the armature structure more stable.