one of the most important factors that affect tire friction is surface roughness, which determines the size of the real contact area, real pressure distribution on the contact interface, and scales of mechanical engagement between viscoelastic rubber and a rough substrate. the need to predict coefficient of friction (cof) for rubber on rough surfaces for applications such as traction of tires o...

coeffcient of  friction  (cof)  for  rubber parts  is one of  the key parameters in their interaction with solid rough surfaces (micrometer to millimeter scales),  such  as  tire-road  interactions. cof  of  rubber  depends  on  viscoelastic properties of rubber, roughness characteristics of the counter-part surface, and process variables such as contact nominal pressure and sliding speed. due ...

The evolution of a friction surface geometry with initially directed microscale grooves on a nanoscale polished surface in ring-on-block sliding contact is studied experimentally. Reduced wear and friction is observed when the orientation of grooves coincides with the direction of sliding. A new compressive-vacuum hypothesis of friction force nature under a condition of boundary lubrication is ...

the friction properties of granular materials play an important role in the determination of specifications for designing hoppers, transporting passages, dryers, silos and machines through which grain flows. in this study, the angle of repose and internal friction coefficient were determined for three common wheat varieties (sardary, gaspard and saysoter) at four moisture contents (12, 15, 18, ...

In-situ sensing the tire–road interactions such as local contact friction force distributions provides crucial information for building accurate friction force models for vehicle safety control. In this paper, we report the development of an embedded, flexible local force sensor for measuring the tire local friction forces and their distributions. A new pressuresensitive, electric conductive ru...

The construction of fast and reliable solvers for contact problems with friction is even nowadays a challenging task. It is well known that contact problems with Coulomb friction have the weak form of a quasi-variational inequality [KO88, HHNL88, NJH80]. For small coefficients of friction, a solution can be obtained by means of a fixed point iteration in the boundary stresses [NJH80]. This fixe...

It is generally assumed that fingerprints improve the grip of primates, but the efficiency of their ridging will depend on the type of frictional behaviour the skin exhibits. Ridges would be effective at increasing friction for hard materials, but in a rubbery material they would reduce friction because they would reduce contact area. In this study we investigated the frictional performance of ...

Smooth contact pads that evolved in insects, amphibians and mammals to enhance the attachment abilities of the animals' feet are often dressed with surface micropatterns of different shapes that act in the presence of a fluid secretion. One of the most striking surface patterns observed in contact pads of these animals is based on a hexagonal texture, which is recognized as a friction-oriented ...

We present experimental data for the static or breakloose friction for lubricated elastomer contacts, as a function of the time of stationary contact. Due to fluid squeeze-out from the asperity contact regions, the breakloose friction force increases continuously with the time of stationary contact. We consider three different cases: (a) PDMS rubber balls against flat smooth glass surfaces, (b)...

adhesion level for the proper running of rail wheelset on track is crucial problem in detecting slippage to avoid accidents. the slippage of rail wheels has been observed applying forward and lateral motions to slip velocity and torsion motion. the longitudinal and lateral forces behavior is watched with respect to traction force to note correlation based on angle of attack. the deriving torque...