High‐pressure science and technology 

About: High‐pressure science and technology is an academic journal. The journal publishes majorly in the area(s): Shock wave & Shock (mechanics). Over the lifetime, 388 publications have been published receiving 1656 citations.

An improved computational constitutive model for brittle materials

Abstract: An improved computational constitutive model for brittle materials is presented. It is applicable for brittle materials subjected to large strains, high strain rates and high pressures, and is well‐suited for computations in both Lagrangian and Eulerian codes. The equivalent strength is dependent on the intact strength, fractured strength, strain rate, pressure, and damage. The pressure includes the effect of bulking, which is introduced through the transfer of internal energy from decreased shear and deviator stresses to potential internal energy associated with increased hydrostatic pressure. Examples are presented to illustrate the model.

Shock response of AD995 alumina

Abstract: This work describes the results of plane shock wave experiments conducted on AD995 (99.5% pure alumina) to 11.3 GPa. with a density of 3.880±0.003 Mg/m3. The results of the shock wave experiments may be summarized as follows: (i) The Hugoniot Elastic Limit of the alumina is 6.71±0.08 GPa; (ii) The spall threshold of the material varies between 0.43 and 0.46 GPa when shock compressed to 8.3 GPa; (iii) The spall threshold of the material becomes negligibly small when shocked above 8.8 GPa; (iv) The deformation behavior of the material above its HEL is quasi‐elastoplastic; (v) The tensile impedance of the material is elastic as long as it has a finite tensile strength and the vanishing of its tensile strength is accompanied by a 70% reduction in its impedance, compared to the elastic impedance.

Brillouin and raman scattering from glasses under high pressure

Abstract: Brillouin and Raman Scattering Spectra in SiO2 and GeO2 glasses have been measured in a diamond anvil cell up to pressures of 14 GPa. The elastic properties and equation of state for each glass type were obtained from the Brillouin scattering measurements with respect to pressure. Both elastic constants and compressibility of SiO2 and GeO2 showed anomalous behavior with respect to pressure. This anomalous behavior is reconciled with a model based on the pressure dependent bending of the oxygen angles in both glass types. The Raman measurements corroborate the conclusions from the Brillouin scattering results, namely that the SiO2 and GeO2 bond angles are changing with pressure or the oxygen angle distribution is changed without bond breaking.

High pressure hugoniot of sapphire

Abstract: The Hugoniot of sapphire was measured for the first time above 145 GPa, from 80 GPa to 340 GPa in shock‐wave experiments using projectiles accelerated by a two stage gas gun. The transit times of the shock waves were measured either optically with a streak camera or through electrical pin contacts. The Hugoniot in this pressure range fits Us=8.74+0.96 Up in km/s.

X-ray study of SnO2 under high pressure and temperature generated with sintered diamond anvils

Abstract: In-situ X-ray diffraction technique using synchrotron radiation was applied for polymorphic transitions in SnO2 under high pressure and temperature generated with 6–8 type double-stage multianvils made of sintered diamond. At 23.6 GPa, the mixed phases of rutile-type structure (R-SnO2) and columbite-type (c-SnO2) were heated: at 700°C peaks of fluorite-type structure (F-SnO2) began to appear, and at 1000°C, C-SnO2 and 5m later R-SnO2 disappeared completely and a single phase of F-SnO2 was recognized, indicating a direct transition from R-SnO2 to F-SnO2. The volume reduction of 5.3% was obtained for C-SnO2→F-SnO2 transition.