Comparison of dynamic behaviour of EMA-3 railgun under differently induced loadings

Comparison of dynamic behaviour of EMA-3 railgun of the French-German Research institute of Saint-Louis (ISL) under differently. induced loadings is presented. Both magnetic pressure loads are generated by two current injections and lead to identical projectile velocities reaching up to 1200 m/s. The main difference between the loads lays in different locations of the injection points. FE simulation results presented in terms of deflections of the sliding rail surface illustrate, that loading differences result into different dynamic behaviours of the railgun. The breech-feed loading, where both injections are induced in the start position of the rail, leads to higher oscillation amplitudes of rail deflections. It was found, that the railgun structure is dynamically less sensitive to the distributed (DES) loading, induced in two different points.