scholarly journals Atomistic mechanisms for frictional energy dissipation during continuous sliding

2021 ◽  
Author(s):  
Sergei Krylov ◽  
Joost Frenken
Keyword(s):  
Energy Dissipation ◽  
Degrees Of Freedom ◽  
Mechanical Energy ◽  
Minor Role ◽  
Destructive Interference ◽  
Phonon Modes ◽  
Mutual Compensation ◽  
Frictional Energy ◽  
Frictional Energy Dissipation ◽  
A Minor

Abstract From a first-principles-based analysis, atomistic mechanisms of frictional energy dissipation are established. For a rigid object moving continuously in the periodic surface potential landscape of a solid that has vibrational degrees of freedom, they can be viewed as (i) the continuous pumping of energy into the resonant modes, if these exist, and (ii) the destructive interference of the force contributions introduced by all excited phonon modes. We report a surprising, mutual compensation between these two basic effects, which leads to very regular oscillations of the dissipative force, with a period determined by half the period of the solid lattice, while the mean friction force experienced by the sliding object hardly depends on time and varies in a straightforward manner with the sliding velocity. These mechanisms act already in a purely dynamic system that includes independent, non-interacting phonon modes, and they manifest irreversibility as a kind of "dynamical stochastization". In contrast to wide-spread views, we show that transformation of mechanical energy into heat, that always takes place in real systems due to the coupling between phonon modes, can play only a minor role in the appearance of friction, if any. This insight into the microscopic mechanisms of energy dissipation opens a new, direct way towards true control over friction.

scholarly journals Atomistic mechanisms for frictional energy dissipation during continuous sliding

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Yu. Krylov ◽  
J. W. M. Frenken
Keyword(s):  
Energy Dissipation ◽  
Degrees Of Freedom ◽  
Sliding Friction ◽  
Mechanical Energy ◽  
Minor Role ◽  
Destructive Interference ◽  
Phonon Modes ◽  
Frictional Energy ◽  
Frictional Energy Dissipation ◽  
A Minor

AbstractAfter more than a century of detailed investigations into sliding friction, we have not arrived yet at a basic understanding of energy dissipation, even for the simple geometry of a rigid slider moving over a perfectly periodic counter surface. In this article, we use a first-principles-based analysis to establish the atomistic mechanisms of frictional energy dissipation for a rigid object that moves continuously in the periodic surface potential landscape of a solid with vibrational degrees of freedom. We identify two mechanisms that can be viewed as (i) the continuous pumping of energy into the resonant modes, if these exist, and (ii) the destructive interference of the force contributions introduced by all excited phonon modes. These mechanisms act already in a purely dynamic system that includes independent, non-interacting phonon modes, and they manifest irreversibility as a kind of “dynamical stochastization”. In contrast to wide-spread views, we show that the transformation of mechanical energy into heat, that always takes place in real systems due to the coupling between phonon modes, can play only a minor role in the appearance of friction, if any. This insight into the microscopic mechanisms of energy dissipation opens a new, direct way towards true control over friction.

scholarly journals On the Origin of Frictional Energy Dissipation

2019 ◽  
Vol 68 (1) ◽  
Author(s):  
Renfeng Hu ◽  
Sergey Yu. Krylov ◽  
Joost W. M. Frenken
Keyword(s):  
Energy Dissipation ◽  
Energy Loss ◽  
Lattice Vibrations ◽  
Scientific Problem ◽  
Frictional Energy ◽  
Slip Event ◽  
Induced Motion ◽  
Frictional Energy Dissipation ◽  
As If

Abstract The origin of the friction between sliding bodies establishes an outstanding scientific problem. In this article, we demonstrate that the energy loss in each microscopic slip event between the bodies readily follows from the dephasing of phonons that are generated in the slip process. The dephasing mechanism directly links the typical timescales of the lattice vibrations with those of the experienced energy ‘dissipation’ and manifests itself as if the slip-induced motion were close to critically damped. Graphical abstract

In‐Plane Potential Gradient Induces Low Frictional Energy Dissipation during the Stick‐Slip Sliding on the Surfaces of 2D Materials

Small ◽  
2019 ◽  
Vol 15 (49) ◽  
pp. 1904613 ◽  
Author(s):  
Feng He ◽  
Xiao Yang ◽  
Zhengliang Bian ◽  
Guoxin Xie ◽  
Dan Guo ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
2D Materials ◽  
Potential Gradient ◽  
Stick Slip ◽  
Frictional Energy ◽  
Frictional Energy Dissipation

Static Axisymmetric Hertzian Contacts Subject to Shearing Forces

1994 ◽  
Vol 61 (2) ◽  
pp. 278-283 ◽  
Author(s):  
R. L. Munisamy ◽  
D. A. Hills ◽  
D. Nowell
Keyword(s):  
Energy Dissipation ◽  
Numerical Method ◽  
Classical Solution ◽  
Dissimilar Materials ◽  
Partial Slip ◽  
Frictional Energy ◽  
Frictional Energy Dissipation

A numerical method is used to resolve the classic Mindlin-Cattaneo partial slip problem for contact between similar and between dissimilar bodies. It is shown that, for similar bodies, the surface frictional energy dissipation is concentrated off the plane of symmetry although the overall dissipation is similar to that predicted by the classical solution. This effect is enhanced for certain combinations of dissimilar materials, where the process of frictional shakedown leads to a displaced contact and hence additional shear compliances.

scholarly journals Wheel-rail dynamics with closely conformal contact Part 2: Forced response, results and conclusions

1997 ◽  
Vol 211 (1) ◽  
pp. 27-40 ◽  
Author(s):  
J Bhaskar ◽  
K. L. Johnson ◽  
J Woodhouse
Keyword(s):  
Energy Dissipation ◽  
Dynamic Models ◽  
Single Point ◽  
Point Contact ◽  
Forced Response ◽  
Normal Displacement ◽  
Transit System ◽  
Frictional Energy ◽  
Frictional Energy Dissipation ◽  
Conformal Contact

The linearized dynamic models for the conformal contact of a wheel and rail presented in reference (1) have been used to calculate the dynamic response to a prescribed sinusoidal ripple on the railhead. Three models have been developed: single-point contact with low or high conformity, and two-point contact. The input comprises a normal displacement Δeiwt together with a rotation Δeiwt applied to the railhead. The output comprises rail displacements and forces, contact creepages and forces, and frictional energy dissipation. According to the Frederick-Valdivia hypothesis, if this last quantity has a component in phase with the input ripple, the amplitude of the ripple will be attenuated, and vice versa. Over most of the frequency range, a pure displacement input (Ψ = 0) was found to give rise, predominantly, to a normal force at the railhead. A purely rotational input (Δ = 0) caused a single point of contact to oscillate across the railhead or, in the case of two-point contact, to give rise to fluctuating out-of-phase forces at the two points. The general tenor of behaviour revealed by the three models was similar: frictional energy dissipation, and hence wear, increases with conformity and is usually of such a phase as to suppress corrugation growth. Thus the association, found on the Vancouver mass transit system, of corrugations with the development of close conformity between wheel and rail profiles must arise from some feature of the system not included in the present models.

Sign in / Sign up

Export Citation Format

Share Document