Mechanism of avalanche precursors in inclining granular layers using a continuum model obtained by discrete element method
| Autor: | Shinichi Yuu, Toshihiko Umekage |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Oscillation General Chemical Engineering Constitutive equation 02 engineering and technology Mechanics Slip (materials science) Granular layer 010402 general chemistry 021001 nanoscience & nanotechnology Granular material 01 natural sciences Discrete element method Physics::Geophysics 0104 chemical sciences Physics::Fluid Dynamics Smoothed-particle hydrodynamics Mechanics of Materials Shear stress 0210 nano-technology |
| Zdroj: | Advanced Powder Technology. 32:2258-2267 |
| ISSN: | 0921-8831 |
| DOI: | 10.1016/j.apt.2021.05.005 |
| Popis: | How do large shear stress and stress ratio peaks, which are avalanche precursors, occur in granular layers in an inclining box and why do the precursors have periodicities? The answers are our main objectives. The large and small shear stress peaks which are constituted by the large and small sticks and slips are found in our simulation results. Small sticks and slips, which occur after the large slip, change the granular structure until the stress ratio becomes equal to or larger than the frictional coefficient of granular materials. Here the next large slip with the large stick and slip, which shows the precursor, occurs. The precursors which are constituted by the series of the large stick–slip events have naturally periodicities because the stick–slip events are oscillation phenomena. Our 3-dimensional simulation results using the smoothed particle hydrodynamics (SPH) method based on our constitutive equations obtained by the 3-dimensional discrete element method (DEM) present the precursors in the bulk and on the surface and show the difference between them. The precursors are also found in the longitudinal and the depth directions of the granular layer. The simulated periodicities agree with the published experimental results. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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