Doctoral Student Named Finalist for APS Student Speaker Award
Thibault Bertrand, a mechanical engineering doctoral student in associate professor Corey O'Hern's lab, has been selected as a finalist for the American Physical Society’s (APS) Group on Statistical & Nonlinear Physics (GSNP) Student Speaker Award for his presentation titled “Shear Jamming in Particulate Media.” Finalists present their research March 3, 2015, at a special session of the annual APS meeting, after which a three-member committee will determine an overall winner.
Bertrand’s presentation concerns the concept of jamming in particulate physics — a physical process by which materials become rigid with increasing density. His research presents evidence that when particles are densely packed into a jammed state, some arrangements of those states are more likely than others; furthermore, the likelihood of achieving certain states is dependent on if the jammed state was achieved through compression or shear.
Bertrand’s research also contradicts previous findings by showing that all the number of possible packings is not dependent on how the jammed state was achieved. “In our simulations, we discovered every possible packing state in a disordered system that contained as few as six particles up to thousands of particles,” said Bertrand. “But no matter the protocol used, we found that there’s nothing intrinsically different about the packings themselves.”
The research has direct applications to the packing industry. For example, a company who separates large quantities of coffee beans into smaller bags will at some point need to stop production when those beans get jammed in the distribution mechanism. Bertrand’s research seeks to understand the fundamental physics that results in such jams, as well as methods for both preventing and resolving these clogs.
The American Physical Society is a non-profit membership organization working to advance and diffuse the knowledge of physics through its outstanding research journals, scientific meetings, and education, outreach, advocacy and international activities. APS represents over 51,000 members, including physicists in academia, national laboratories, and industry in the United States and throughout the world. The objective of the GSNP is the advancement and dissemination of knowledge in the interdisciplinary area of nonequilibrium statistical physics, including the emerging field of soft condensed matter physics.