Publications Details
Strength of porous α-SiO2 in a shock loaded environment
Hudspeth, Matthew; Olles, Joe; Williams, James R.; Mandal, Anirban; Root, Seth R.; Vogler, Seth
The strength of brittle porous media is of concern in numerous applications, for example, earth penetration, crater formation, and blast loading; thus it is of importance to possess techniques that allow for constitutive model calibration within the laboratory setting. It is the goal of the immediate work to demonstrate an experimental technique allowing for strength assessment, which can be implemented into pressure dependent yield surfaces within numerical simulation schemes. As a case study, the deviatoric strength of distended α-SiO2 has been captured in a tamped Richtmyer- Meshkov instability environment at a pressure regime of 4-10 GPa. In contrast to traditional RMI studies used to infer strength in solids, the described approach herein is implemented to probe the behavior of the porous tamp media backing the corrugated solid surface. Hydrocode simulation has been used to interpret the experiment, and a resulting pressure-dependent yield surface akin to the often employed Modified Drucker-Prager model has been calibrated via the coupled experiment and simulation. The simulations indicate that the resulting jet length generated by the RMI is highly sensitive to the porous media strength, thereby providing a feasible experimental platform capable of capturing pressurized granular deviatoric response. Additionally, a Mach lens loading environment has also been implemented as a validation case study, demonstrating good agreement between experiment and simulation within an alternative loading environment. Calibration and validation of the pressure-dependent yield surface gives confidence to the model form, thereby providing a framework for future porous media strength studies.