the equations governing the motion of steel balls and their impact onto shell liners in industrial semi-autogenous grinding (sag) mills are derived in full details by the authors and are used in order to determine the effective design variables for optimizing the working conditions of the mill and to avoid severe impacts which lead to the breakage of sag mill shell liners. these design variable...

Friction has an important influence in metal forming operations as it contributes to the success or failure of the process. In the present investigation, the effect of friction on metal forming was studied by conducting compression tests of cylindrical Al-Mg alloy using Finite Element Method (FEM) technique. Three kinds of compression tests were performed. For the first test, a constant coeffic...

uniaxial compressive strength (ucs) and internal friction coefficient (µ) are the most important strength parameters of rock. they could be determined either by laboratory tests or from empirical correlations. the laboratory analysis sometimes is not possible for many reasons. on the other hand, due to changes in rock compositions and properties, none of the correlations could be applied as an ...

Cylindrical telescopic crowns belong to bolt dentures, because their adhesion strength is based on the friction force. The magnitude of static and slide friction forces depends on the strain within the contact area and properties of materials employed. Friction force value between telescope elements declines in the first phase of wearing period and, subsequently, maintains particular constant v...

Slippery surfaces are a continuous concern in equine veterinary practice during both treatment and orthopaedic work-ups, especially when horses have to trot on circles. Sliding of the equine foot on the ground with the potential of injury is prevented if the horizontally acting accelerating or decelerating forces on the foot do not exceed maximal friction. Friction can be calculated and therefo...

Aiming at predicting what happens in reality inside mills, the contact parameters of iron ore particles for discrete element method (DEM) simulations should be determined accurately. To allow the irregular shape to be accurately determined, the sphere clump method was employed in modelling the particle shape. The inter-particle contact parameters were systematically altered whilst the contact p...

Hyaluronan, lubricin and phospholipids, molecules ubiquitous in synovial joints, such as hips and knees, have separately been invoked as the lubricants responsible for the remarkable lubrication of articular cartilage; but alone, these molecules cannot explain the extremely low friction at the high pressures of such joints. We find that surface-anchored hyaluronan molecules complex synergistica...

We present a theoretical, numerical, and experimental study about the sliding motion of an angular particle down a vibrated smooth plane. The model is based on a Coulomb's friction law with a unique friction coefficient. The model is solved numerically and is tested with controlled experiments. Different motion regimes are identified and the particle behavior is governed by two dimensionless pa...

A kind of 2.5-dimensional C/C-SiC composites was fabricated by using Isothermal Chemical Vapour Infiltration process (ICVI). Frictional properties of this material were evaluated by using MM-1000 under dry condition. Average dynamic friction coefficient of it was 0.16, static friction coefficient and average coefficient stability were 0.15 and 0.56, respectively. However, weight wear rate was l...