A new and better way to predict earthquakes and avalanches may soon be available to forecasters thanks to mathematical research underway at NJIT. Using mathematical modeling, researchers are investigating how forces and pressures propagate through granular materials.
"Computational Homology, Jamming and Force Chains in Dense Granular Flows," a four-year, $378,603 National Science Foundation grant has been awarded to Louis Kondic, associate professor of mathematical sciences at NJIT. Kondic will study how the physical properties of granular materials, like sand or salt, can lead to jamming, large force fluctuations and ultimately how they can pressure a building to topple. Both earthquakes and avalanches involve similar materials and reactions.
"The mystery is to learn how forces and pressure propagate or move through grains," said Kondic. "We know the answer for liquids, but for granular materials, we do not. As a result, it is difficult to build efficient devices for dealing with them. Silos can collapse due to non-uniform pressures on their walls. Salt, sand or coal often jams when flowing out of hoppers. But why they behave like this remains unknown."
2006, Kondic was the co-author of "On Velocity Profiles and Stresses in Sheared and Vibrated Granular Systems Under Variable Gravity" which appeared in Physics of Fluids. Other articles by him investigating similar research have appeared in Applied Mathematics and Mechanics (2008), SIAM News (2007) and Physics Review E (2005).
(ATTENTION EDITORS: To receive copies of the articles or to interview Kondic, call Sheryl Weinstein, 973-596-3436.)
The current project centers on so-called force chains, which are crucial for understanding granular systems. The attached figure shows computer simulations of heterogeneous, ramified structures (colored yellow). "Similar forces do not propagate uniformly, but instead form chain-like structures," sai
|Contact: Sheryl Weinstein|
New Jersey Institute of Technology