It has been shown recently that steady frictional sliding along an interface between dissimilar elastic solids with Coulomb friction acting at the interface is ill-posed for a wide range of material parameters and friction coefficients. The ill-posedness is manifest in the unstable growth of interfacial disturbances of all wavelengths, with growth rate inversely proportional to the wavelength. ...

A discrete-time sliding mode control design for a ball-screw driven positioning table is presented. The basic feature of this design is that high speed and high positioning accuracy can be met despite of the fact that the controlled process suffers from friction and mechanical flexibility. Disturbance rejection, in the form of friction compensation and vibration suppression, is the main focus o...

In general, machine military technique part wear does not depend only on the friction characteristics (rolling or sliding friction), but it is a complex physicalchemical process that occurs on sliding surfaces of the tribological units. An external, undesirable product of the friction system activity is a very wide spectrum of wear particles. With respect to diagnostics it is important that the...

The static friction preventing the free sliding of nanosized rare gas solid islands physisorbed on incommensurate crystalline surfaces is not completely understood. Simulations modeled on Kr/Pb(111) highlight the importance and the scaling behavior of the island's edge contribution to static friction.

Friction is a complicated phenomenon involving nonlinear dynamics at different length and time scales. Understanding its microscopic origin requires methods for measuring force on nanometer-scale asperities sliding at velocities reaching centimetres per second. Despite enormous advances in experimental technique, this combination of small length scale and high velocity remain elusive. We presen...

Rate-and-state friction is an empirical approach to the behavior of a frictional surface. We use a nematic liquid crystal in a channel between two parallel planes to model frictional sliding. Nematic liquid crystals model a wide variety of physical phenomena in systems that rapidly switch between states; they are well studied and interesting examples of anisotropic non-Newtonian fluids, charact...

Our recent experimental work showed that asymmetry is needed for surface textures to decrease friction in full-film lubricated sliding (e.g. thrust bearings) with Newtonian fluids; textures reduce the shear load and produce a separating normal force [1]. However, standard slider bearing theory cannot explain the sign of the observed normal thrust, and any effort to optimize surface textures wou...

The friction between concentric carbon nanotubes sliding one inside the other has been widely studied and simulated, but not so far using external force as the driving variable. Our molecular dynamics (MD) simulations show that as the pulling force grows, the sliding velocity increases by jumps and plateaus rather than continuously as expected. Dramatic friction peaks (similar to that recently ...

In web transport systems, the main concern is to independently control speed and tension in spite of perturbations such as radius variations and changes of setting points. So far, simulation models representing web handling systems have only dealt with continuously rolling web without considering friction between web and rollers. This article aims at introducing the modeling of friction as well...

In this paper, a novel robust adaptive sliding-mode control scheme is presented high precision position control for a permanent magnet synchronous linear motor (PMSLM) servo system under the influence of unknown parameters, nonlinear friction, cogging forces, and external distance. The proposed strategy effectively combines the design techniques of adaptive control and sliding-mode control. In ...