Assessment of the response of rocket propellants to high-velocity projectile impact using small-scale laboratory tests

Abstract

Two small-scale laboratory testing methods (Hopkinson Bar and Shotgun tests) for assessing the response of rocket propellants to high-velocity projectile impact are described. The impact ignition sensitivities of several composite propellants and cast double base (CDB) propellants have been determined. Composite propellants with different mechanical properties, oxidizer loading, and oxidizer and binder types, and CDB propellants with different nitrocellulose (NC)-to-nitroglycerine (NG) ratios have been examined. The two tests give comparable results, except for very “soft” propellants. Results from the Hopkinson Bar and Shotgun tests correlate with bullet impact field trials of end-burning rocket motors and suggest that the information obtained from these small-scale tests are relevant to propellant ignition and burning and can predict, to some extent, the response of rocket propellants to projectile impact.