Bulletin of the American Physical Society
18th Biennial Intl. Conference of the APS Topical Group on Shock Compression of Condensed Matter held in conjunction with the 24th Biennial Intl. Conference of the Intl. Association for the Advancement of High Pressure Science and Technology (AIRAPT)
Volume 58, Number 7
Sunday–Friday, July 7–12, 2013; Seattle, Washington
Session K7: ME.4 Strength V |
Hide Abstracts |
Chair: Justin Brown, Sandia National Laboratories Room: Grand Crescent |
Tuesday, July 9, 2013 1:45PM - 2:15PM |
K7.00001: The effect of microstructure on Rayleigh-Taylor instability growth in solids Invited Speaker: Russell Olson The effect that grain size and material processing have on high-strain rate deformation of copper and tantalum has been assessed through measurements of unstable Rayleigh-Taylor (RT) perturbation growth. The dynamic loading conditions and initial sinusoidal perturbations imposed on the samples are kept constant while the microstructure of the sample material is varied. Different polycrystalline grain-sizes, single-crystal orientations, and strain-hardened samples have all been dynamically tested. The RT perturbation growth is measured by acquiring a time-sequence of radiographs using the Los Alamos National Laboratory Proton Radiography (pRad) Facility. Single-crystal orientation and stain hardening due to material processing are both observed to affect the perturbation growth. However, polycrystalline grain size variations in both tantalum and copper samples do not influence the growth rate under the loading conditions investigated.\\[4pt] In collaboration with Ellen Cerreta, Christopher Morris, Adam Montoya, Fesseha Mariam, Alexander Saunders, Robert King, Eric Brown, George Gray and John Bingert, Los Alamos National Laboratory. [Preview Abstract] |
Tuesday, July 9, 2013 2:15PM - 2:45PM |
K7.00002: Explosively driven two-shockwave tools with application to ejecta formation at the Los Alamos National Laboratory Proton Radiography Facility Invited Speaker: William Buttler We present the development of an explosively driven physics tool to generate two mostly uniaxial shockwaves. The tool is being used to extend single shockwave ejecta models to a subsequent shockwave event separated by a time interval on the order of a few microseconds. We explore the possibility of varying the amplitude of both the first and second shockwaves, and we apply the tool in experimental geometries on Sn with a surface roughness of $R_a = 0.8 \mu$m. We then evaluate the tool further at the Los Alamos National Laboratory Proton Radiography (pRad) Facility in an application to Sn with larger scale perturbations of wavelength $550 \mu$m, and various amplitudes that gave wave-number amplitude products of $\eta_0 2 \pi / \lambda = \{3/4, 1/2, 1/4, 1/8\}$, where the perturbation amplitude is $\eta_0$, and the wave-number $k = 2 \pi / \lambda$. The pRad data and velocimetry imply it should be possible to develop a second shock ejecta model based on unstable Richtmyer-Meshkov physics.\\[4pt] In collaboration with David Oro, Fesseha Mariam, Alexander Saunders, Malcolm Andrews, Frank Cherne, James Hammerberg. Robert Hixson, Christopher Morris, Russell Olson, Dean Preston, Joseph Stone, Dale Tupa, and Wendy Vogan-McNeil, Los Alamos National Laboratory, [Preview Abstract] |
Tuesday, July 9, 2013 2:45PM - 3:00PM |
K7.00003: Measurement of the Response of an Elastomer at Pressures Up to 9GPa and Strain Rates of $10^{5}-10^{6}s^{-1}$ Tong Jiao, Rodney Clifton Pressure-shear plate impact (PSPI) experiments have been conducted to study the mechanical response of an elastomer at high pressures and high strain rates. The previously determined isentrope has been extended to 9 GPa. At this pressure, the high-strain-rate shearing resistance of polyurea is approximately 500MPa- comparable to, or greater than, that of high strength steels and at much lower weight. It was also found that polyurea exhibits remarkable ``recoil'' during unloading from these high pressures. A new symmetric pressure-shear plate impact (SPSPI) configuration has been developed in order to enable the direct measurement of the thickness-averaged nominal strain rates of the sample - as well as the tractions on both of its interfaces with linear elastic plates. This enhancement is made possible by using a symmetric configuration for which the velocity of the mid-plane of the sample is known from symmetry to be one-half of the impact velocity. One-dimensional elastic wave theory is used to obtain tractions and particle velocities at the sample/anvil interface from the measured rear-surface velocities. In this way, nominal strain-rate histories are obtained for both longitudinal and shear strains. [Preview Abstract] |
Tuesday, July 9, 2013 3:00PM - 3:15PM |
K7.00004: Preheating study by VISAR measurements in laser-driven shocks on SGII facility Xiuguang Huang, Hua Shu, Sizu Fu, Junjian Ye, Zhihen Fang, Guo Jia, Zhiyong Xie, Huazhen Zhou, Tao Wang The preheating of laser-irradiated aluminum planar or multi-step targets has been measured by velocity interferometer system for any reflector (VISAR), which detects the target's rear surface motion prior to shock wave breakout. The preheating temperature was induced from the linear expansion theory and release isentrope data, respectively. And the results calculated from both methods are consistent. The results also show that the preheating temperature decreases nearly linear with decreasing laser energy or increasing foil's thickness. Moreover, the preheating effects drop sharply by only burying a thin high-Z layer ($\sim$1.5$\mu $m Au) in the aluminum foil. Base on above results and other results from X-ray crystal spectrometer, electron energy spectrometer, and our analytical calculation, we think that the source of preheating is mainly of hard X-ray. [Preview Abstract] |
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