We study the effects of temperature and sliding velocity on superlubricity in numerical simulations of the Frenkel-Kontorova model. We show that resonant excitations of the phonons in an incommensurate sliding body lead to an effective friction and to thermal equilibrium with energy distributed over the internal degrees of freedom. For finite temperature, the effective friction can be described...

I thankLockner et al. [this issue], hereafter referred to as LBS, for their interest in this work. LBS suggest that I [Marone, 1995] misunderstood their analysis and that their proposed empirical relation is indeed valid. I do not agree. I do not deny that LBS have established some form of empirical relationship, only the specific form of the relation and its theoretical basis are at issue. The...

A brake hardware-in-the-loop simulation (HILS) system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component's purpose and interaction with other compo...

Abrasive flow polishing plays an important part in modern ultra-precision machining. Ultrafine particles suspended in the medium of abrasive flow removes the material in nanoscale. In this paper, three-dimensional molecular dynamics (MD) simulations are performed to investigate the effect of impacting direction on abrasive cutting process during abrasive flow polishing. The molecular dynamics s...

Experiments were conducted to determine the effects of frequency and amplitude of vibration on friction. The experimental analysis also seeks to take into account a variety of factors influencing the coefficient of friction such as normal load and surface roughness. An in-house pin-on-disc apparatus was constructed with a spindle speed control and applied forced-feedback to perform the tests. T...

OBJECTIVE This study tests the hypothesis that the natural progression of osteoarthritis (OA) in human joints leads to an increase in the friction coefficient. This hypothesis is based on the expectation that the wear observed in OA may be exacerbated by higher friction coefficients. A corollary hypothesis is that healthy synovial fluid (SF) may help mitigate the increase in the friction coeffi...

the influence of surface roughness magnitude and direction on dry static friction coefficient between two similar steel samples has been studied through an experiment. a testing apparatus has been designed and fabricated to measure the friction coefficient for a few forms of surface asperity. according to the results of the experiments, dry friction coefficient is affected by both magnitude and...

OBJECTIVE To investigate the effects of lubricin gene dosage and cyclic loading on whole joint coefficient of friction and articular cartilage surface integrity in mouse knee joints. METHODS Joints from mice with 2 (Prg4(+/+)), 1 (Prg4(+/-)), or no (Prg4(-/-)) functioning lubricin alleles were subjected to 26 hours of cyclic loading using a custom-built pendulum. Coefficient of friction value...

nt matter & 2007 IAgrE. temseng.2007.02.013 thor. Tel.: +1 217 333 2854; : [email protected] (T.E. Gri This paper describes the development of a device capable of measuring the dynamic friction coefficient of particles accelerated in a tube spinning in a horizontal plane. The dynamic friction coefficient is not the classical Coulomb friction coefficient, but a lumped parameter influenced by the Co...

Distinctly quantum friction effects of three types are surveyed: internal friction, measurement-induced friction, and quantum-fluctuation-induced friction. We demonstrate that external driving will lead to quantum internal friction, and critique the measurement-based interpretation of friction. We conclude that in general systems will experience internal and external quantum friction over and b...