Rolling contact fatigue is a common failure mode in gears and bearings. However, this getting greater attention due to the increasing tendency use lower viscosity lubricants reduce losses. Though several types of research have been done over past decades, there are still scopes for further investigations. This study aims effect slide roll ratios (SRR), surface roughness treatment on wear pittin...

The stiffness of micron-sized sphere-plate contacts was studied by employing high frequency, tangential excitation of variable amplitude (0-20 nm). The contacts were established between glass spheres and the surface of a quartz crystal microbalance (QCM), where the resonator surface had been coated with either sputtered SiO2 or a spin-cast layer of poly(methyl methacrylate) (PMMA). The results ...

Electric trains are powered by a current distribution device which depends on several parameters. The research works presented in this paper located upstream of two types important applications the railway field: electrical supply involving sliding or stationary pantograph/catenary contact and famous problem shunting wheel/rail rolling contact. These cannot be assumed without energy loss. In ca...

Electro-mechanical actuators including planetary roller screw (PRS) support cyclic loads in aeronautical conditions. PRS multiple thread contacts between screw, rollers and nut allow the mechanism to large loads. However, accreditation requires fine prediction of fatigue lifespan. In this paper, a design strategy for mechanisms is proposed combining Hertz contact model multi-axial criterion. Th...

Abstract Adhesion and friction between solids in ambient air control applications such as precision positioning traction of tires. For all practical surfaces, the interfaces are rough. Contact occurs at nano- or micro-contact junctions contact area these changes upon normal shear loading during sliding. The multiscale roughness, material parameters interfacial bonding, mechanical properties, sl...

Abstract Laboratory measurements can determine the potential for geologic materials to generate unstable (seismic) slip, but a direct relation between sliding behavior in laboratory and physical characteristics observable field is lacking, especially phyllosilicate-rich gouges that are widely observed natural faults. We integrated friction experiments with surface topography microscopy demonstr...

This paper evaluates state-of-the-art contact models at predicting the motions and forces involved in simple in-hand robotic manipulations. In particular it focuses on three primitive actions—linear sliding, pivoting, and rolling—that involve contacts between a gripper, a rigid object, and their environment. The evaluation is done through thousands of controlled experiments designed to capture ...

In [19] we presented a model of nonprehensile manipulation, using two one-degree-of-freedom palms. Under the assumptions of low friction and quasistatic motion, we developed a planning method for part reorientation with our model, starting from a known initial state. Our method finds feasible paths through the space of equivalent state configurations of the object in the palms, without requirin...

We examine numerically the yielding or failure of small granular packings subjected to an increasing deviatoric stress. As the load increases, the packing softens and the number of sliding contacts rises. When the packing fails, the kinetic energy starts to rise exponentially in time. It is always possible to identify a contact status change that triggers the collapse of the packing. Furthermor...