Bulletin of the American Physical Society
16th APS Topical Conference on Shock Compression of Condensed Matter
Volume 54, Number 8
Sunday–Friday, June 28–July 3 2009; Nashville, Tennessee
Session E4: ID-3: Shock Response of Brittle Materials |
Hide Abstracts |
Chair: C. Scott Alexander, Sandia National Laboratories Room: Hermitage D |
Monday, June 29, 2009 3:30PM - 3:45PM |
E4.00001: Shock Loading of polycrystalline alumina and sapphire--a comparative study Geremy Kleiser, Lalit Chhabildas, William Reinhart There is considerable interest in the shock loading behavior of aluminum oxide whether it is in the polycrystalline phase or in the single crystal phase. Results of well-controlled experiments conducted recently on polycrystalline alumina and Z- cut sapphire at Sandia National Laboratories are summarized to conduct a comparative study. Although the experimental results appear to have the same behavior in the shock-velocity vs. particle-velocity plane, they are considerably different in the stress-volume compression plane. This is an extremely interesting observation and cannot be explained merely by the differences in the strength of the material in the shocked state. [Preview Abstract] |
Monday, June 29, 2009 3:45PM - 4:00PM |
E4.00002: Shock compression of AD95 alumina J.X. Peng, C.M. Hu, Z.F. Sun, P. Li, H.L. He The continuum dynamic response of AD95 alumina under shock compression has been investigated. Symmetry planar impact coupling with velocity interferometry was used to measure the shock-release wave profiles over the stress range of 20-60 GPa. These results show that an elastic-plastic double wave structure still exists in AD95 alumina. Analysis indicates that, instead of a linear relationship, the relation between particle-velocity and shock-velocity agrees well with a quadratic equation. The Hugoniot elastic limit and spall strength have been obtained as well in these stress range. [Preview Abstract] |
Monday, June 29, 2009 4:00PM - 4:15PM |
E4.00003: Shock Response of Silicon Nitride D.P. Dandekar, D.T. Casem, Y. Motoyashiki, E. Sato Silicon nitride is suitable for varied applications. The properties of silicon nitride have been tailored through processing and doping. The current work presents shock response of silicon nitride marketed as SN282. The density of this material, 3.4 Mg/m$^{3}$, exceeds its single crystal density due to the presence of lutetium oxide as an additive in ca. 5{\%} by weight in the material. While the average grain size is 3.4 microns, aspect ratio of the grains exceed 3. Preliminary results of shock wave experiments may be summarized as follows: (1) The Hugoniot Elastic Limit (HEL) of SN282 is 11.2 GPa. (2) The magnitude of the inelastic wave velocity just above the HEL is 8.73 km/s, suggesting that inelastic deformation above the HEL is due to shock induced plasticity in the material. (3) The estimated value of the spall strength is 0.5 GPa. The spall strength of SN282 remains unchanged even when shocked beyond the HEL. The non-vanishing spall strength suggests that doping plays a role in the retention of spall strength of SN282. The role of doping needs to be further investigated. [Preview Abstract] |
Monday, June 29, 2009 4:15PM - 4:30PM |
E4.00004: Study of Compressive Strength of SiC In Impact Experiments with Divergent Flow Vitaly Paris, Naum Frage, Eugene Zaretsky The axisymmetric divergent flow was generated in SiC specimens by impact of spherical (radius of curvature ranging from 170 to 550 mm) copper impactors having velocities 550 to 700 m/s. The specimen-window (sapphire) interface velocities or the velocities of the free surface of the nickel witness plate were continuously monitored by VISAR. The maximum, just prior to the failure, shear stress values achieved in the SiC under different confining stresses are associated with the failure threshold of the material. Both the compressive failure threshold of SiC and the parameters of its inelastic deformation were found by matching the results of the AUTODYN numerical simulation to the experimentally obtained waveforms. The compressive failure threshold of SiC is characterized by a transition from apparently pressure-dependent behavior below the confining stress equal to 1.5 GPa to a pressure-independent behavior at higher confining stresses. [Preview Abstract] |
Monday, June 29, 2009 4:30PM - 5:00PM |
E4.00005: On failure in polycrystalline and amorphous brittle materials Invited Speaker: The response of brittle materials to uniaxial compressive shock loading is still not well understood. Describing the physical mechanisms resulting from the more complex triaxial states that result from impact and penetration is thus empirical. The physical interpretation of the yield point of brittle materials in one-dimensional strain (the Hugoniot elastic limit (HEL)), the rate dependence of this threshold, the form of stress histories and the effect of polycrystalline microstructure still remain to be comprehensively explained. However, evidence of failure occurring in glasses and ceramics behind a travelling front that follows a shock front has been accumulated and verified in several laboratories. Such a boundary has been called a failure front. The variations in properties across this front include complete loss of tensile strength, partial loss of shear strength, reduction in acoustic impedance, lowered sound speed and opacity to light. It is the object of this work to collect observations of these phenomena and their relation to failure and the HEL in brittle materials. Further, to relate these uniaxial strain measurements of their failed states to the depth of penetration (DoP) in the widely conducted test. British Crown Copyright MoD/2009. [Preview Abstract] |
Monday, June 29, 2009 5:00PM - 5:15PM |
E4.00006: Loading Path Dependence of Inelastic Behavior: X-cut Quartz Seth Root, James Asay Shock and shockless compression methods were used to examine the loading path dependence of single crystal x-cut quartz. In these experiments, x-cut quartz samples were dynamically compressed to stresses above the Hugoniot elastic limit. An analysis of the transmitted wave profiles show remarkably different behavior between shock and shockless loaded samples. Shock loaded x-cut quartz shows inelastic deformation below 5 GPa. Ramp loaded samples, however, do not show significant inelastic behavior until approximately 10 GPa, with the onset of this behavior dependent on sample thickness. The results demonstrate that both loading path and loading rate play important roles in the inelastic behavior of materials. [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