Sliding friction across a thin soft lubricant film typically occurs by stick slip, the lubricant fully solidifying at stick, yielding and flowing at slip. The static friction force per unit area preceding slip is known from molecular dynamics (MD) simulations to decrease with increasing contact area. That makes the large-size fate of stick slip unclear and unknown; its possible vanishing is imp...

A new procedure for deriving nonlinear mathematical modeling for a specific class of aerospace hydro - mechanical control valves is presented. The effects of friction on the dynamic behavior of these types of valves along with the experimental verifictions are also given. The modeling approach is based on the combination of the following three tasks: decomposition of the valve into simple speci...

The main purpose of this study was to examine the effect of chalk on the friction coefficient between climber's fingers and two different rock types (sandstone and limestone). The secondary purpose was to investigate the effects of humidity and temperature on the friction coefficient and on the influence of chalk. Eleven experienced climbers took part in this study and 42 test sessions were per...

The onset of frictional motion is mediated by rupture-like slip fronts, which nucleate locally and propagate eventually along the entire interface causing global sliding. static friction coefficient a macroscopic measure applied force at this particular instant when loses stability. However, experimental studies are known to present important scatter in measurement friction; origin remains unex...

The paper aims at investigating the effects of chemical reaction and thermal radiation on the steady two-dimensional laminar flow of viscous incompressible electrically conducting micropolar fluid past a stretching surface embedded in a non-Darcian porous medium. The radiative heat flux is assumed to follow Rosseland approximation. The governing equations of momentum, angular momentum, energy, ...

The process of size segregation in a model system of granular matter, consisting of 1600 spherical poly-disperse particles stirred by a rectangular bar moving periodically in the horizontal direction, was modelled by the discrete element method under different values of dynamic friction coefficient of the particle material. It has been shown that the dynamic friction coefficient influences the ...

Friction is the result of complex interactions between contacting surfaces in a nanoscale perspective. Depending on the application, the di erent models available are more or less suitable. Available static friction models are typically considered to be dependent only on relative speed of interacting surfaces. However, it is known that friction can be a ected by other factors than speed. In thi...

Two varieties of Pearl millet seeds (Penisetum glaucum) (Ex-Borno and SOSAT C88) were obtained from the Lake Chad Research Institute, Maiduguri-Nigeria and reconditioned to moisture contents ranging from 10% 20% w.b. The reconditioned seeds were then evaluated for dimensions, sphericity, bulk density, solid density, porosity, thousand seed mass, angle of repose and static coefficient of frictio...

The correlations between pavement texture and tire pressure with the actual tire-road contact area were first investigated according to static characteristics; on this basis, influence mechanisms of speed friction coefficient systematically explored from angle coupling system dynamics via self-developed dynamic testing tire-pavement friction. By integrating above factors, BP neural network meth...