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Title: Shear Heating of Explosives using the Crush Gun; FY2018 Report

Abstract

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 wasmore » 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.« less

Authors:
 [1]; ORCiD logo [1]; ORCiD logo [1];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1482908
Report Number(s):
LA-UR-18-30889
DOE Contract Number:  
89233218CNA000001
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE

Citation Formats

Holmes, Matthew David, Rae, Philip John, Haroz, Erik Hector, and Erickson, Michael Andrew Englert. Shear Heating of Explosives using the Crush Gun; FY2018 Report. United States: N. p., 2018. Web. doi:10.2172/1482908.
Holmes, Matthew David, Rae, Philip John, Haroz, Erik Hector, & Erickson, Michael Andrew Englert. Shear Heating of Explosives using the Crush Gun; FY2018 Report. United States. doi:10.2172/1482908.
Holmes, Matthew David, Rae, Philip John, Haroz, Erik Hector, and Erickson, Michael Andrew Englert. Thu . "Shear Heating of Explosives using the Crush Gun; FY2018 Report". United States. doi:10.2172/1482908. https://www.osti.gov/servlets/purl/1482908.
@article{osti_1482908,
title = {Shear Heating of Explosives using the Crush Gun; FY2018 Report},
author = {Holmes, Matthew David and Rae, Philip John and Haroz, Erik Hector and Erickson, Michael Andrew Englert},
abstractNote = {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.},
doi = {10.2172/1482908},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2018},
month = {11}
}

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