| Autor: |
Clark AH; Department of Physics, Naval Postgraduate School, Monterey, California 93943, USA., Brodsky EE; Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, California 95064, USA., Nasrin HJ; Naval Surface Warfare Center, Carderock Division, Bethesda, Maryland 20817, USA., Taylor SE; Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, California 95064, USA. |
| Abstrakt: |
We computationally study the frictional properties of sheared granular media subjected to harmonic vibration applied at the boundary. Such vibrations are thought to play an important role in weakening flows, yet the independent effects of amplitude, frequency, and pressure on the process have remained unclear. Based on a dimensional analysis and DEM simulations, we show that, in addition to a previously proposed criterion for peak acceleration that leads to breaking of contacts, weakening requires the absolute amplitude squared of the displacement to be sufficiently large relative to the confining pressure. The analysis provides a basis for predicting flows subjected to arbitrary external vibration and demonstrates that a previously unrecognized second process that is dependent on dissipation contributes to shear weakening under vibrations. |
