The determination of launch induced static and dynamic rail deflection of a Benet 50 mm railgun barrel

The design of railgun projectiles requires a knowledge of rail deflection caused by electromagnetic forces generated during a launch. Sufficient armature-to-rail contact force must be maintained as the projectile passes through the bore. A hydraulic jack has been custom designed and built to fit inside a 5 m/spl times/50 mm composite overwrap railgun barrel designed and built by Benet Weapons Lab. A displacement transducer installed in the jack was used to obtain data leading to the determination of the spring constant of the rail´s elastic foundation. This paper presents the use of the rail jack data in determining the static/dynamic rail deflection due to electromagnetic distributed loading in the Benet railgun barrel. Additionally, the concept of critical armature velocity as applied to railguns is introduced.<>