An Analysis of EM Railgun Cross Section Designs

In order for a railgun to function properly, the distance between the rails needs to stay nearly constant throughout the length of the shot.The same magnetic force that propels the projectile out the barrel works to pull the rails apart.If they get pulled too far apart, the armature may lose contact with the rails and cause significant problems.Ben t s job was to help mitigate this by building a railgun with a stiff cross section that holds the rails together while keeping the overall weight of the system low.To achieve a stiff cross section, Ben t incorporated a preload into the wrap of the design.The preload was incorporated to counteract the electromagnetic forces and keep the rails from expanding beyond acceptable limits, and testing and simulations verify that having a preload in the design performs much better than the same design without preload.This was proven through the use of experiments and finite element analysis on several designs, but most notably on an adaptation of the XM1 design from a previous Army EM gun program. The original document contains color images.