电磁轨道发射时,导轨和电枢都有强电流通过,从而在导轨间形成强磁场并在电枢上作用有强大的推动力.由于流经两侧导轨的电流方向相反产生了相互作用的斥力,电枢在强电流作用下产生了焦耳热使得电枢膨胀.考虑到导轨对电枢膨胀位移的限制,则电枢对导轨的侧面形成压力.通过通入的直流电流的密度来计算两导轨间相互作用的斥力的集度,由此可将导轨简化成受有一段分布载荷和一个刚印作用下梁的力学模型,并应用共形映射将其变换到下半平面上,利用柯西积分可求得电枢与导轨接触面附近的局部应力场,其计算成果可为导轨的强度设计提供依据.
The strong current will discharge in the armature and rail when the electromagnetic rail is at a launching state. As a result,strong magnetic field appears between the rails,and applies a strong driving force on the armature. The opposite direction currents flowing through both sides of the rails can arise from repulsion interaction; at the same time, the armature expands because of the Joule heat generated by strong current. Taking into account restriction imposed by the rail on the transverse displacement of the armature, the armature forms the pressure on the side of rail. In order to solve it, the intensity of interaction repulsive force is calculated through the discharged direct current density, and then the rail is simplified to a beam subject to a uniformly distributed load and a concentrated force. Conformal mapping is employed to transform it to lower half-plane,and the Cauchy integral is adopted to calculate the local stress field near contact surface between armature and rail. These results can provide theoretical bases for strength design of the rail.