Bulletin of the American Physical Society
17th Biennial International Conference of the APS Topical Group on Shock Compression of Condensed Matter
Volume 56, Number 6
Sunday–Friday, June 26–July 1 2011; Chicago, Illinois
Session Q6: Ballistics IV: Armors and Protection |
Hide Abstracts |
Chair: Stephen Recchia, U.S. Army ARDEC Room: Grand Ballroom VI |
Wednesday, June 29, 2011 4:00PM - 4:15PM |
Q6.00001: Ballistic Performance of Porous-Ceramic, Thermal Protection Systems Joshua Miller, William Bohl, Eric Christiansen, B. Alan Davis, Cory Foreman Porous-ceramic, thermal protection systems are used heavily in current reentry vehicles like the Orbiter, and they are currently being proposed for the next generation of US manned spacecraft, Orion. These systems insulate reentry critical components of a spacecraft against the intense thermal environments of atmospheric reentry. Additionally, these materials are also highly exposed to space environment hazards like solid particle impacts. This paper discusses impact testing up to 9.65 km/s on one of these systems. The materials considered are 8 lb/ft$^{3}$ alumina-fiber-enhanced-thermal-barrier (AETB8) tiles coated with a toughened-unipiece-fibrous-insulation/reaction-cured-glass layer (TUFI/RCG). A semi-empirical, first principals impact model that describes projectile dispersion is described that provides excellent agreement with observations over a broad range of impact velocities, obliquities and projectile materials. A model extension to look at the implications of greater than 10 GPa equation of state measurements is also discussed. Predicted penetration probabilities for a vehicle visiting the International Space Station is 60{\%} lower for orbital debris and 95{\%} lower for meteoroids with this model compared to an energy scaled approach. [Preview Abstract] |
Wednesday, June 29, 2011 4:15PM - 4:30PM |
Q6.00002: Testing Boron Carbide and Silicon Carbide under Triaxial Compression Charles Anderson, Sidney Chocron, Arthur Nicholls Boron Carbide (B4C) and silicon carbide (SiC-N) are extensively used as armor materials. The strength of these ceramics depends mainly on surface defects, hydrostatic pressure and strain rate. This article focuses on the pressure dependence and summarizes the characterization work conducted on intact and predamaged specimens by using compression under confinement in a pressure vessel and in a thick steel sleeve. The techniques used for the characterization will be described briefly. The failure curves obtained for the two materials will be presented, although the data are limited for SiC. The data will also be compared to experimental data from Wilkins (1969), and Meyer and Faber (1997). Additionally, the results will be compared with plate-impact data. [Preview Abstract] |
Wednesday, June 29, 2011 4:30PM - 4:45PM |
Q6.00003: Experimental and Computational Study of Water Blast Mitigation Associated with Different Water Configurations Andrew Zakrajsek, Eric Miklaszewski, Steven Son An explosion yielding a shock wave is just one of the many threats the US faces. This threat can cause damage to equipment, structures, and cause significant risk to personnel. These threats define an immediate importance for understanding blast mitigation techniques via readily available mitigants. Specific blast mitigation techniques using water are being studied. Four fundamentally different water configurations are being considered. The fundamental mitigation mechanisms such as momentum transfer, large impedance differences, and evaporation are being explored. Laboratory testing using an explosively driven shock tube and a pressurized air shock tube are used for configurations including: solid water barriers, water sprays, water sheets, and individual droplets of water. Trends observed will be explained based on simulations coupled with known droplet breakup phenomena and analysis. We will report on experimental results and analysis, in addition to discussing the various blast mechanisms associated with each testing configuration. [Preview Abstract] |
Wednesday, June 29, 2011 4:45PM - 5:00PM |
Q6.00004: Scaled Long Rod Penetration Experiments: Tungsten - RHA William Proud Scaled, reverse ballistic, long-rod experiments were performed at an impact velocity in the range of $\sim $700 m s-1. The targets were tungsten alloy rods and the projectiles either 3 or 6 mm thick rolled homogeneous armour (RHA) plates. The plate was inclined at 30\r{ } to the direction of travel and the interaction was recorded using high-speed photography, strain gauges and laser velocimetry. The pitch of the rod was varied in steps of 3\r{ } over a total range of 15\r{ }. In this range the rod deformation changed dramatically the bending process moved from a flexing of the tip away from the plate, to a marked motion into the surface. Cross comparison of the diagnostic outputs reveals the time windows for these process and also the varying sensitivity of the measurement system to that process. Post-impact recovery was also performed. [Preview Abstract] |
Wednesday, June 29, 2011 5:00PM - 5:15PM |
Q6.00005: Burst Pressure Failure of Titanium Tanks Damaged by Secondary Plumes from Hypervelocity Impacts on Aluminum Shields Henry Nahra, Louis Ghosn, Eric Christiansen, B. Alan Davis, Christopher Keddy, Karen Rodriguez, Joshua Miller, William Bohl Metallic pressure tanks used in space missions are inherently vulnerable to hypervelocity impacts from micrometeoroids and orbital debris; thereby knowledge of impact damage and its effect on the tank integrity is crucial to a spacecraft risk assessment. This paper describes tests that have been performed to assess the effects of hypervelocity impact (HVI) damage on Titanium (Ti) pressure vessels burst pressure and characteristics. The series consists of a pair of HVI impact tests on water-filled Ti tanks (water as a surrogate to the propellant) and subsequent burst tests of these tanks and an undamaged control tank. The tanks were placed behind Aluminum (Al) shields and then each was impacted with a 7 km/s projectile. The resulting impact debris plumes partially penetrated the Ti tank surfaces resulting in a distribution of craters. During the burst tests, the tank that failed at a lower burst pressure did appear to have the failure initiating at a crater site with observed spall cracks. A fracture mechanics analysis that provides insight into how the cracks associated with a spall site initiate a failure cascade is discussed. [Preview Abstract] |
Wednesday, June 29, 2011 5:15PM - 5:30PM |
Q6.00006: ABSTRACT WITHDRAWN |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700