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 ...

in this paper, finite element elastic contact analysis of a functionally graded (fg) hollow brake disk in contact with pad, subjected to rotation, contact pressure and frictional heat is presented. the material properties vary through the thickness according to a power-law characterised by a grading index, n. the material property is purely steel at the core part and gradually moves and approac...

Polyethylene wear is a great concern in total joint replacement. It is now considered a major limiting factor to the long life of such prostheses. Cross-linking has been introduced to reduce the wear of ultra-high-molecular-weight polyethylene (UHMWPE). Computational models have been used extensively for wear prediction and optimization of artificial knee designs. However, in order to be indepe...

Recent direct implementation of asperity theories is reinterpreted here to formulate an improved version of the Greenwood and Williamson GW) theory with the inclusion of interaction between asperities. This is achieved by treating the contact pressures as uniformly distributed over he apparent contact area and the resulting deformation as uniform. The correction is equivalent to an increase of ...

This paper describes the relationship between the rates of charge transport (by tunneling) across self-assembled monolayers (SAMs) in a metal/SAM//Ga2O3/EGaIn junction and the geometric contact area (Ag) between the conical Ga2O3/ EGaIn top-electrode and the bottom-electrode. Measurements of current density, J(V), across SAMs of decanethiolate on silver demonstrate that J(V) increases with Ag w...

The friction coefficient between a guide and a tape sample is determined experimentally as a function of nominal tension, speed and guide radius. A comparative study between metal particulate and metal evaporated tape is performed. The tape/guide contact pressure correlated to the experimental results. Tape temperature measurements are compared with the experimentally obtained friction coeffici...

abstract: compaction under tractors tires is of special concern because the weight of these machines has increased dramatically in the last years. these machines and others associated with crop cultural practices weight enough to significantly compact the soil, especially if the soil is soft with high moisture content during tilling, planting, or harvesting. the stress distribution and the size...

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)...

In many constructions, their elements are in contact with nominally matching (congruent) surfaces. reality, this is disturbed due to deviations the shape of these surfaces from nominal. To study effect perturbation on distribution pressure, analysis stress-strain state body system punched sheet-die carried out. The middle element deviates flat shape. This causes a change pressure distribution. ...