Research On The Finited Element Calculation And Simulation Of C-Shaped Armature Used For Electromagnetic Launch

Electromagnetic rail lauch technology, with its military application forground and huge potential, attracts the main military countries to study it on both theory and application. Amature takes an important role in the whole lauch process. The solid C-shaped armature is a common used type in the researches of electromagnetic rail lauch recently.High current density centralization in one part could lead to a high partial temperature in C-shaped armatures, makes the rail and armature material melted down, eroded and fracted in consequence. The force distribution on armature is also affected by the currend density distribution. In the process of electromagnetic rail launch, it requires the device keeping solid metal-metal contact between armature and rail nodes, without transition. The volumn of contact pressure between armature and rail nods is an important element affecting transition happens or not. Therefore it's necessary to design armature reasonable to improve the current density distribution in armature.In order to make the effects of various parameters in process of electromagnetic launch clear, on the assumption of the nondisjunction and ideal entire contact between the armature and the rails, this paper analysed the inner current field distribution, and the consequently temperature field and electromagnetic force distribution characters of C-shaped armature in the launching process based on ANSYS.The calculation was done with establishing the modle devided. The principle of using stepped resistence material in C-shaped armature affects current density distribution is got. When deviding the model inside to out, the inner layers was found carrying higher current density. By increasing resistence of inner layers, the current density distribution in armature became equaler and the differences of max volumns of current density in each layer smaller. In the model devided in Z-axis, more current density is observed flowing from middle layers, and the density became smaller to bottom or top layers. When making the resistence of armature smaller and smaller from the ends to middle, the current density distribution in armature became equaler and the differences of max volumns of current density in each layer smaller.The effects of current volumn and variate ratio acts on the Y-axis electromagnetic forces on armature was calculated and analysed. In the same variate ratio, the force grads on armature were increasing, along with the increase of current volumn. The max volumn of Y-axis forces on the nodes, has a direct raio to the square of current volumn. In the different current variate ratio and the same current volumn, the max volumn of Y-axis forces on the nodes keeps the same, but the distributions of the forces had an obviously difference. As the results of the distribution difference, the electromagnetic force has a positive effect on the contact of armature and rails while the current increasing, and a negative effect while the current decreasing.A set of zero speed electromagnetic launch experiments were introduced at the end of this paper. The results of simulation and experiments were compared, a conclusion is the simulated results were consistent with the experiments'results in consequence.