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arXiv · 1311.1690

Probing locally the onset of slippage at a model multi-contact interface

V. Romero·E. Wandersman·G. Debrégeas·A. Prevost
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Abstract

We report on the multi-contact frictional dynamics of model elastomer surfaces rubbed against bare glass slides. The surfaces consist of layers patterned with thousands spherical caps (radius of curvature 100 $μ$m) distributed both spatially and in height, regularly or randomly. Use of spherical asperities yields circular micro-contacts whose radius is a direct measure of the contact pressure distribution. In addition, optical tracking of individual contacts provides the in-plane deformations of the tangentially loaded interface, yielding the shear force distribution. We then investigate the stick-slip frictional dynamics of a regular hexagonal array. For all stick phases including the initial one, slip precursors are evidenced. They are found to propagate quasi-statically, normally to the iso- pressure contours. A simple quasi-static model relying on the existence of interfacial stress gradients is derived and predicts qualitatively the position of slip precursors.

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V. Romero, E. Wandersman, G. Debrégeas, A. Prevost. 2013-11-07. Probing locally the onset of slippage at a model multi-contact interface. https://doi.org/10.1103/physrevlett.112.094301

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