Granule shear behaviour was investigated experimentally and numerically to evaluate the reliability of the numerical model. Additionally, parameters affecting the ensuing flow regimes - elastic quasi-static and inertial non-collisional - were highlighted. Furthermore, the influence of using the Lees-Edwards periodic boundary conditions or the standard boundary conditions was studied. Experiment...

Large deposits of coal over vast expanse of lands attract mining companies, power stations and petrochemical companies and thus the development of coal towns with rail and road networks. High traffic volume of large quantities of coal across coal cities often result in the gradual accumulation of fine coal dust particles on road pavements, rail ballast and sleepers. The effect of coal dust on t...

The shear failure and friction mechanisms of bioinspired adhesives consisting of elastomer arrays of microfibres terminated by mushroom-shaped tips are investigated in contact with a rigid lens. In order to reveal the interplay between the vertical and lateral loading directions, experiments are carried out using a custom friction set-up in which normal stiffness can be made either high or low ...

A number of problems of dynamic deformation in the presence of moving contact surfaces are considered. A grid characteristic method using a two-dimensional irregular triangular grid and a hybrid scheme with 1-2 order of approximation is adapted. An algorithm for calculating the force of friction and the force of static friction is proposed. The numerical solution to wheel rolling and shear wave...

Atomically flat and clean metal surfaces exhibit a regime of ultra-low friction at low normal loads. Atomic force microscopy, performed in ultra-high vacuum on Cu(100) and Au(111) surfaces, reveals a clear stick-slip modulation in the lateral force but almost zero dissipation. Significant friction is observed only for higher loads (*4– 6 nN above the pull-off force) together with the onset of w...

[1] A significant portion of the ice discharge in ice sheets is drained through ice streams, with subglacial sediment (till) acting as a lubricant. The known importance of horizontal friction in shear margins to ice stream dynamics suggests a critical role of longitudinal stresses. The effects of subglacial till and longitudinal stresses on the stability of an ice sheet flow are studied by line...

In the present study, plate impact pressure±shear friction experiments are conducted to provide insight into timeresolved dry sliding characteristics of metal on metal at normal pressures of approximately 1.5 GPa, slip speeds up to 60 m/s and interfacial temperatures as high as 8008C. The plate impact friction experiments represent a signi®cant improvement over conventional dynamic friction exp...

The static friction coefficient between two materials is considered to be a material constant. We present experiments demonstrating that the ratio of shear to normal force needed to move contacting bodies can, instead, vary systematically with controllable changes in the external loading configuration. Large variations in both the friction coefficient and consequent stress drop are tightly link...

Field observations of major earthquake fault zones show that shear deformation is often confined to principal slipping zones that may be of order 1–100 μmwide, located within a broader gouge layer of order 10–100 mm wide. This paper examines the possibility that the extreme strain localization observed may be due to the coupling of shear heating, thermal pressurization, and diffusion. In the ab...

When pulling a particle in a driven granular fluid with constant force Fex, the probe particle approaches a steady-state average velocity v. This velocity and the corresponding friction coefficient of the probe ζ=Fex/v are obtained within a schematic model of mode-coupling theory and compared to results from event-driven simulations. For small and moderate drag forces, the model describes the s...