Refining FE structural mechanics simulations of a railgun by taking into account electromagnetic effects

Abstract

The modeling of the structural mechanics of an electromagnetic railgun can in a first approach be done without considering details of the magnetic pressure. The latter is assumed to be a boundary condition in a mechanical problem. Even this approximation proves to be a great challenge, as spatially moving pressure profiles at speeds of a railgun projectile are very rare in purely mechanical investigations. In this contribution we ask the question, if such an approach is accurate. As a first step, we calculate the 3-D distribution of the J×B volume force density in the rails and use them as input for our structural mechanics model. A second point concerns the electromechanical behavior of parts made from conducting materials, such as the steel bolts we use to counter the repelling forces between the rails. We use the ANSYS package for our numerical investigations.