PPPS-2013: Anti-shock analysis of the electromagnetic launched missile

Abstract

The missile launched by the conventional artillery is accelerated by the gas pressure, while the electromagnetic launched missile is accelerated by the electromagnetic force. Accordingly, there are three main differences between them. Firstly, as for the electromagnetic launch, when the muzzle velocity is precisely controlled, the driving current applied on the rail changes according to the difference between the desired and the measured velocity1, resulting in the change of the force acting on the missile more complex. Secondly, the electromagnetic launched missile reaches the maximum acceleration within a shorter time, and keeps it for a longer time. Thirdly, in the electromagnetic launching process, the missile is accelerated by the armature2. When the launching process is completed, in order to improve the controllability and flexibility of the missile, the missile must be separated from the armature. Therefore, the missile is not fixed with the armature together. When there is a gap between the armature and the missile, at the beginning of the launching process, the armature accelerated by the strong electromagnetic force obtains a large momentum in quite a short time, so there is an impact after the contact of the armature and the missile, which does not exist in the conventional artillery. As a result, the anti-shock design of the electromagnetic launched missile against high overload becomes very difficult. In this paper, an anti-shock device design method, taking into account the single-degree-of-freedom system dynamics and the modal analysis, was proposed. Through reasonable simplification, the finite element model including printed circuit and other components was created using the finite element analysis software ANSYS/LS-DYNA. And then the anti-shock performance of the important components of the device under impact circumstance was researched through the shock dynamic response results obtained. Based on theoretical analysis and numerical simulation, the anti-shock performance of the electronic devices on electromagnetic launched missile is improved through several methods, including adding damping elements, raising the stiffness of the devices, change of the distribution of electronic components, and etc. Comparing the different methods above, the optimization design is proposed, which could improve the anti-shock performance a lot. The research in this paper would be a reference in improving the anti-shock design of the electromagnetic launched missile.