A shallow-layer model for granular flows is completed with a closure relation for the macroscopic bed friction or basal roughness obtained from micro-scale discrete particle simulations of steady flows. We systematically vary the bed friction by changing the contact friction coefficient between basal and flowing particles, while the base remains geometrically rough. By simulating steady uniform...

metal forming processes, compared with machining ones, reduce production steps and increasemanufacturing speed in addition to saving raw material. in this paper, forming process of column ofa steering mechanism is investigated by finite element analyses and experimental tests; andoptimum die design parameters are found. forming process parameters including die opening angle,bearing length, clea...

The aim of our research was to indicate the suitability metallurgical slags (two blast furnace and one steel slag) as components Cu-free friction materials. base mixture consisted nine including phenolic resin, graphite, tin sulphide, aramid fibers, iron powder, a barite with calcite, vermiculite. To this mixture, particle size below 0.1 mm were added individually in amount 20 wt.%. A alumina w...

One of the great challenges in the processing of materials using Equal Channel Angular Pressing (ECAP) is the high forming forces required to produce large shear deformation in the material. Researchers show that the friction forces between the die and the sample constitute a great part of the total forming forces. Recently, ultrasonic vibrations are successfully implemented into the ECAP proce...

It is generally assumed that fingerprints improve the grip of primates, but the efficiency of their ridging will depend on the type of frictional behaviour the skin exhibits. Ridges would be effective at increasing friction for hard materials, but in a rubbery material they would reduce friction because they would reduce contact area. In this study we investigated the frictional performance of ...