Static and Dynamic Strength of Scarf-Repaired Thick-Section Composite Plates

Abstract : One of the many challenges facing weapon developers is the requirement for a highly lethal, lightweight, and compact large caliber gun system. One concept recently investigated by the U.S. Army is that of a swing-chamber gun, necessitating the use of telescoped ammunition. Such ammunition not only reduces the volume available for the propellant change, but also places severe geometric constraints on both the distribution of the propellant and the location and functionality of the ignition system. Lumped parameter codes cannot capture the influence of these configurational complexities on the processes of flame spreading and the formation of ensuing pressure waves. One-dimensional, two-phase flow interior ballistic simulations reveal the likelihood of such waves and raise the concern for possible damage to the ammunition (projectile). Multidimensional, two-phase interior ballistic simulations provide quantitative predictions of the flow in the annular region between the sidewall of the telescoped projectile and the cartridge case, also show the formation of pressure waves, and further the concern over projectile damage. Initial results are shown from ongoing work to couple an interior ballistics code with a gun/projectile structural dynamics code. Pressure waves in the charge produce a very demanding environment for the projectile which necessitates the use of a more substantial structure, with the attending sharp reduction in cargo capacity, or the use of exotic materials in order to insure a successful launch.