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The Role of Fabric in Frictional Properties of Phyllosilicate-Rich Tectonic Faults
Published on: November 6, 2021
Rolling friction on a granular medium
Fabio Vittorio De Blasio1, May-Britt Saeter
1Department of Geosciences, University of Oslo, P.O. Box 1047 Blindern, 0316 Oslo, Norway.
Summary
This study on rolling spheres found a consistent friction coefficient across various speeds. Larger spheres traveled farther, potentially explaining rock sorting in natural environments.
Area of Science:
- Physics
- Granular Mechanics
- Experimental Physics
Background:
- Rolling motion on granular surfaces involves complex interactions.
- Understanding granular dynamics is crucial for various scientific and engineering fields.
Purpose of the Study:
- To experimentally investigate the rolling motion of spheres on a granular bed.
- To determine the friction coefficient and its dependence on velocity and sphere properties.
- To explore factors influencing rolling distance and potential real-world applications.
Main Methods:
- Utilized glass and steel spheres of varying diameters.
- Employed a high-speed camera to meticulously track sphere motion.
- Conducted experiments on a granular bed to simulate rolling conditions.
Main Results:
- Observed a friction coefficient largely independent of velocity.
- Measured friction coefficients of 0.45-0.5 for glass spheres and 0.6-0.65 for steel spheres.
- Found that larger spheres achieved greater rolling distances for a given density.
Conclusions:
- The friction coefficient during sphere rolling on granular beds is velocity-independent.
- Sphere size influences rolling distance, with larger spheres traveling farther.
- These findings may elucidate the mechanism of rock sorting observed in natural geological formations.
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01:09Rolling Without Slipping
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01:05Static and Kinetic Frictional Force
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01:14Rolling With Slipping
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