Modeling friction: from nano to meso scales

Source: arXiv


The physics of sliding friction is gaining impulse from nano and mesoscale
experiments, simulations, and theoretical modeling. This colloquium reviews
some recent developments in modeling and in atomistic simulation of friction,
covering open-ended directions, unconventional nanofrictional systems, and
unsolved problems.

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Available from: Stefano Zapperi
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    • "The energies barriers (high energy regime) and saddles (low energy regime) existed in the PES. In stick-slip frictional model,[48] a force has to be applied to overcome the energy barrier along the sliding path. Overcoming the energy barrier has to be applied a large force, which led to increasing the friction. "
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    ABSTRACT: Generally, amorphous carbon films sliding against Al2O3 ceramics ball exhibited low friction. However, the low friction mechanism was still not well understood. Since the atomic interaction has difficulty in observing from the experimental method. Thus, in this paper, we probed the origin of low friction mechanism of amorphous carbon films against Al2O3 ceramics ball based on first principles calculations. The work of separation did not well illustrate the low friction mechanism. The calculated results of the potential energy surface showed that the minimum energy paths, which defined as a series of low energy regimes of the potential energy surface, were in charge of the low friction.
    Full-text · Article · Oct 2015 · Surface and Coatings Technology
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    ABSTRACT: Non-equilibrium molecular dynamics simulations, of crucial importance in sliding friction, are hampered by arbitrariness and uncertainties in the removal of the frictionally generated Joule heat. Building upon general pre-existing formulation, we implement a fully microscopic dissipation approach which, based on a parameter-free, non-Markovian, stochastic dynamics, absorbs Joule heat equivalently to a semi-infinite solid and harmonic substrate. As a test case, we investigate the stick-slip friction of a slider over a two-dimensional Lennard-Jones solid, comparing our virtually exact frictional results with approximate ones from commonly adopted dissipation schemes. Remarkably, the exact results can be closely reproduced by a standard Langevin dissipation scheme, once its parameters are determined according to a general and self-standing variational procedure.
    Full-text · Article · Aug 2012 · Tribology Letters
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    ABSTRACT: In a pioneer experiment, Bohlein et al. realized the controlled sliding of two-dimensional colloidal crystals over laser-generated periodic or quasi-periodic potentials. Here we present realistic simulations and arguments that besides reproducing the main experimentally observed features give a first theoretical demonstration of the potential impact of colloid sliding in nanotribology. The free motion of solitons and antisolitons in the sliding of hard incommensurate crystals is contrasted with the soliton-antisoliton pair nucleation at the large static friction threshold F(s) when the two lattices are commensurate and pinned. The frictional work directly extracted from particles' velocities can be analyzed as a function of classic tribological parameters, including speed, spacing, and amplitude of the periodic potential (representing, respectively, the mismatch of the sliding interface and the corrugation, or "load"). These and other features suggestive of further experiments and insights promote colloid sliding to a unique friction study instrument.
    Preview · Article · Sep 2012 · Proceedings of the National Academy of Sciences
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