EVENT DETAILS
Experimental Micromechanics of 3D Granular Materials with Applications to Force Chains, Waves, Rearrangements, Length Scales
Abstract
Granular materials are the sands, soils, and powders that are ubiquitous in nature and technology. Traditional approaches to studying granular materials include discrete and continuum modeling, 2D experiments using model materials, and 3D experiments using X-ray computed tomography (XRCT). While modeling approaches provide crucial predictions of material behavior across length scales, their quantitative validation in terms of both kinematics and stresses remains a challenge. Furthermore, while experimental techniques such as XRCT provide in-situ data on particle kinematics, they do not provide stress fields needed to fully constrain constitutive laws and link microscopic energy dissipation mechanisms to macroscopic deformation.
In this talk, I will first discuss our experimental approach to studying the micromechanics of 3D granular materials that combines in-situ XRCT and 3D X-ray diffraction (3DXRD), an X-ray scattering technique that provides per-particle stress tensors in thousands of crystalline particles simultaneously. I will then discuss exciting applications of our experiments, including for studying: inter-particle force networks in granular materials, ultrasound wave behavior, the microscopic origins of macroscopic energy dissipation, the role of packing structure and particle stress in local rearrangements, and the length scales governing representative volume element sizes of various material properties.
Bio
Dr. Ryan Hurley is an Assistant Professor in the Department of Mechanical Engineering and a Fellow of the Hopkins Extreme Materials Institute at the Johns Hopkins University (JHU). He received his B.S. in Civil Engineering from the University of Maryland, College Park (2011) and his M.S. and Ph.D. in Applied Mechanics from the California Institute of Technology (2012 and 2015). From 2015 - 2017, Ryan was a postdoctoral researcher in the Computational Geosciences Group at Lawrence Livermore National Laboratory in Livermore, California and an Assistant Research Professor at JHU. He joined JHU full-time as an Assistant Professor in January 2018. He received the Department of Energy's Secretary's Appreciation Award in 2017 for his work on the Source Physics Experiment and a 2020 NSF CAREER award. Ryan's interests include studying the deformation and failure mechanisms of granular materials, rocks, concrete, and ceramics using advanced experimental techniques and modeling approaches.
TIME Wednesday April 14, 2021 at 11:00 AM - 12:00 PM
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CONTACT Tierney Acott tierney.acott@northwestern.edu
CALENDAR McCormick - Civil and Environmental Engineering