Transient Resonance in Hypervelocity Launchers at Critical Velocities

A projectile accelerating along launcher rails may cross a range of critical velocities and induce resonance. As a result, the rails and other components exhibit increased displacements and stress that may cause launcher failure. This work is focused on the computation of the critical velocity and investigation of the transient resonance in the assembly of a notional electromagnetic hypervelocity launcher. Several analytical and finite-element models were employed. Different models yielded a good correlation and aided in better understanding of the launcher dynamics. Analysis shows that various components of a launcher can have different critical velocities. The results of this work will further be used to develop a novel design approach based on the idea of controlling the intervals between the critical velocities to minimize the enhanced occurrence of induced resonance regimes in launcher assemblies.