Solid materials usually contain damage in the form of small voids. If filled with a liquid, these voids can serve as nucleation sites for water to change phase from liquid to gaseous state if sudden pressure changes occur. If the solid structure is subjected to a sudden high-impulse dynamic impact, stress waves are generated and will propagate through the solid and the liquid-filled voids. When subjected to sudden changes in pressure, small bubbles within the liquid-filled voids have the potential to rupture, or cavitate, and emit liquid jets and shockwaves that can increase the damage to the surrounding solid. As the liquid undergoes cavitation, the complex physics of the cavitation bubbles and subsequent jetting will determine how the surrounding solid deforms and breaks. The goal of this research is to use experiments to quantify the resulting deformation in real time with high-speed, non-invasive visualization techniques. The fractured specimens will be post-processed to further evaluate the difference between various scenarios.
If successful, this cross-disciplinary project, integrating fluid mechanics theory with solid mechanics and fracture dynamics, will provide an important step towards understanding the failure modes of solids during highly dynamic short duration tests to assess the strength of structures and lead to viable options to minimize or avoid damage. This project opens new venues for interesting applications, with examples ranging from wave slamming on coastal structures and earthquake impact on dam buildings to non-invasive treatment of kidney stones. This project will support one PhD student at University of Southern California. With focus on promoting the participation of underrepresented groups, undergraduate and high-school students will be invited to work on short-term summer projects related to this research.
