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...

BACKGROUND Prevention of slipping accidents requires provision of adequate friction through the use of suitable combinations of footwear and underfoot surfaces. Shoe sole tread groove is one of the important factors on friction coefficient during walking. OBJECTIVE To measure the effect of different shoe sole tread groove depths and different surfaces on the required quotient of friction (Q),...

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...

Single asperity friction experiments using atomic force microscopy (AFM) have been conducted on chemical vapor deposited (CVD) graphene grown on polycrystalline copper foils. Graphene substantially lowers the friction force experienced by the sliding asperity of a silicon AFM tip compared to the surrounding oxidized copper surface by a factor ranging from 1.5 to 7 over loads from the adhesive m...

-A pressure-shear plate impact experiment is introduced to study time-resolved friction at interfaces subjected to high sliding speeds under relatively high normal pressures. The conditions of slip at the interface are varied by changing the surface roughness of the impacting plates and by varying the applied normal to shear stress ratio. The configuration offers the simplicity of allowing the ...

Friction originates at the area of real contact which depends on (changing) surface topography. Observing and measuring multi-asperity interfaces is difficult, making it challenging to quantitatively study interplay between frictional force In this paper, we systematically manipulate topography use a fluorescence microscopy-based visualization technique reveal interplay. We demonstrate good agr...

This paper describes a computational method to calculate the friction force between two rough surfaces. In the model used, friction results from forces developed during elastic deformation and shear resistance of adhesive junctions at the contact areas. Contacts occur between asperities and have arbitrary orientations with respect to the surfaces. The size and slope of each contact area depend ...

in this research, the effect of surface roughness and bubble injection on skin friction and hydrodynamic drag force has been numerically considered. this research is based on taylor-couette flow. considered flow includes two concentric cylinders which internal cylinder is movable and external is immovable. the effective equations on the flow includes: equations of momentum, continuous, turbulen...

TaN films with different N2 partial pressure were deposited on 304 stainless steel using the magnetron sputtering method. The effect of gas pressure on the mechanical property, morphology and phase structure of the films is investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), microhardness testing, friction coefficient measurements, and wear mechanism study. The XRD results c...