It has been widely recognized that there are influences of static friction characteristics in a bolted joint on pre-tightening and service reliability. This study proposed coefficient model surfaces based the modified three-dimensional fractal model. A method measuring was investigated to verify accuracy The results showed calculated value measured experiment highly matched. Furthermore, influe...

In rehabilitation training, high-fidelity simulation environments are needed for reproducing the effects of slippery surfaces, in which potential balance failure conditions can be reproduced on demand. Motivated by these requirements, this article considers the design of variable-friction devices for use in the context of human walking on surfaces in which the coefficient of friction can be con...

The progression of local cartilage surface damage toward early stage osteoarthritis (OA) likely depends on the severity of the damage and its impact on the local lubrication and stress distribution in the surrounding tissue. It is difficult to study the local responses using traditional methods; in-situ microtribological methods are being pursued here as a means to elucidate the mechanical aspe...

The inhomogeneous distribution of surface asperities generated by deformation induces variability in the friction and initiates strain localizations during metal forming. The friction literature generally does not account for the strong influence localized variations in material properties have on the friction behavior. A prototype apparatus was developed that measures the friction behavior und...

With nanotextured surfaces and interfaces increasingly being encountered in technological and biomedical applications, there is a need for a better understanding of frictional properties involving such surfaces. Here we report friction measurements of several nanostructured surfaces using an Atomic Force Microscope (AFM). These nanostructured surfaces provide well defined model systems on which...

We examine the characteristics of helical flow in a concentric annulus with radii ratios of 0.52 and 0.9, whose outer cylinder is stationary and inner cylinder is rotating. Pressure losses and skin friction coefficients are measured for fully developed flows of water and a 0.4% aqueous solution of sodium carboxymethyl cellulose (CMC), when the inner cylinder rotates at the speed of 0~62.82 rad/...