Shear Heating of Explosives using the Crush Gun; FY2018 Report
Explosives subject to rapid mechanical deformation can experience large internal velocity gradients; this is a dissipative process, causing internal temperature rise. If this internal frictional heating is sufficiently large and sufficiently localized it can cause ignition of the explosive. Modeling the heat deposition that arises from mechanical insult is an ongoing effort, and additional experimental data is required to develop the model [1]. Apneumatic gun apparatus was designed and built to deliver crushing impacts at velocities of 0-70 m/s. The apparatus is designed to halt the projectile approximately 1 mm before impacting the sapphire imaging surface, preventing a complete “pinch” condition from attaining. The primary diagnostics include high-speed visible videography and infrared imaging to determine spatial temperature rise of the sample during impact. Forty-seven tests were performed with the apparatus during FY18, on four different explosives: Comp-B, PBX 9501, LX-07, and LX-14.No measurable heating was observed with Comp-B at a nominal velocity of 58 m/s. A maximum temperature rise of 17 °C was recorded with PBX 9501 at an impact velocity of 59 m/s. A maximum temperature rise of 32 °C was observed with LX-07 at an impact velocity of 57 m/s. A maximum temperature rise of 15 °C was observed with LX-14 at an impact velocity of 59 m/s. In contrast to drop-weight tower sensitivity testing [2,3], no ignitions were observed in any of the impacts. The lack of appreciable heating is attributed to the arrest mechanism which prevents the projectile from completing the final ~2 mm of crush. Differences between the explosive compositions are attributed primarily to binder effects.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- DOE Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1482908
- Report Number(s):
- LA-UR-18-30889
- Country of Publication:
- United States
- Language:
- English
Similar Records
Case Penetration and Detonator Crush FY2019 Report
Slide Test FY 2019 Report