Characterisation of model asperity flattening under longitudinal subsurface elongation is presented with a variety normal pressure, flank angle and strain hardening behaviour. A systematic investigation outlines an optimal specimen design to ensure homogenous deformation field in the workpiece stress-strain conditions, which are typical sheet metal forming. Asperity increases reduces necessary ...

The effect of an asymmetric distribution of asperity heights is accounted for in a recently developed scale-dependent multiasperity model of contact and friction. A Weibull distribution of asperity heights is used which allows the skew and kurtosis to be varied, but not independently of each other. The contact and friction model used includes the effects of adhesion and of scale-dependent frict...

Friction between two objects can be understood by the making, stretching, and breaking of thousands of atomic-scale asperities. We have probed single atoms in a nonisotropic surface [the H-terminated Si(100) surface] with a lateral force microscope operating in noncontact mode. We show that these forces are measurably different, depending upon the direction. Experimentally, these differences ar...

We used near-field and regional GNSS (Global Navigation Satellite System) data to quantify the deformation locking ratio of Xiaojiang fault (XJF) in southeastern Tibet. The inversion based on dislocation model shows that slip rate XJF is 9–11 mm/a; depths northern, central, southern segments are 25.5 km, 12 22.5 respectively. with DEFNODE program northern segment strongest above a depth 20 whil...

The purpose of this research paper is to examine the tribological characteristics and issues related to journal bearings under boundary and mixed lubrication conditions during shaft startup, shutdown, and low speeds. The key issues and problems related to journal bearings, most notably wear, are discussed as well as the subsequent issues created in the field. The mechanical analysis of the load...

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...