Title: High Pressure Granular Mechanics at Low and High Strain Rates

Author (Invited): Ryan Hurley, Johns Hopkins University

Abstract:

Granular materials experience high pressures in pharmaceutical processing, during many manufacturing practices, in geophysical events such as earthquakes and landslides, and during planetary and projectile impacts. Under high pressures, grains break, rearrange, fill pore space, and may plastically deform. Continuum breakage mechanics (CBM) and pore collapse models have emerged as key concepts for describing high pressure events in granular materials. Here, I introduce these concepts and describe the latest methods for studying high pressure granular mechanics in the context of such models. I will discuss the latest advances in low strain rate laboratory testing that permit direct 3D visualization and quantification of breakage, flow, and strain localization through in-situ X-ray imaging. I will discuss implications of this work for predicting geophysical and impact phenomena. I will also discuss advances in high-strain-rate testing that permit direct 2D visualization of pore collapse, and advances in digital twin modeling which enable us to study the visualized events in 3D. The audience will leave the talk with an appreciation of several tools and concepts that may be leveraged to study granular materials under high pressures.