Using frictional force microscopy (FFM), the friction surface characteristics were compared between twisted nematic (TN) mode and vertical alignment (VA) mode alignment films (AFs). The friction asymmetry was detected depending on temperature conditions on TN mode AF, but not on VA mode AF. The difference between two modes was explained by leaning intermolecular repulsion caused by the pre-tilt...

A new approach for estimating the interfacial frictional shear stress in fiber-reinforced ceramics is presented. The approach is based upon measurement of the temperature rise which occurs during the cyclic loading of ceramic composites. This temperature rise, which is caused by the frictional slip of fibers within the composite, is related to the level of frictional shear stress which exists a...

We consider dynamic problems which describe frictional contact between a body and a foundation. The constitutive law is viscoelastic or elastic and the frictional contact is modelled by a general subdifferential condition on the velocity, including the normal damped responses. We derive weak formulations for the models and prove existence and uniqueness results. The proofs are based on the theo...

a r t i c l e i n f o Recent high-resolution GPS and seismological data reveal that tectonic faults exhibit complex, multi-mode slip behavior including earthquakes, creep events, slow and silent earthquakes, low-frequency events and earthquake afterslip. The physical processes responsible for this range of behavior and the mechanisms that dictate fault slip rate or rupture propagation velocity ...

High precision applications, such as, semiconductor manufacturing and diamond turning of optical elements require positioning accuracy within nanometers and therefore require very precise motion control of machine tool axes. The frictional behavior at the slides is a result of very complex interaction between the contacting surfaces and lubricants. No accurate quantitative prediction of the fri...

We present novel results on flow properties using molecular dynamics simulation as well as γ -densitometry experiments. We show that fundamentally different types of granular flow can be observed in one unique system. Using both frictional and frictionless confining walls, we show that the differences existing between these regimes originate in the frictional properties of the walls. The salien...

Energy savings by reducing the thermal and mechanical losses in machines is of major concern due to continuous depletion of energy resources. Frictional losses of engine components cause energy losses leading to high fuel consumption. In piston assembly, piston skirt and liner interaction contribute as much as a frictional loss as the piston rings but more studies have been focused on piston ri...

The nonlinear frictional behavior of two-dimensional (2-D) and three-dimensional (3-D) models are compared in this study of fides in the Bight of Abaco. The shallow depths and the existence of an extensive set of tidal elevation data (five astronomical and two overtide constituents at 25 stations) from Filloux and Snyder (1979) offer an excellent opportunity to compare the effects of different ...

There are several applications in robotics and manufacturing in which nominally rigid objects are subject to multiple frictional contacts with other objects. In most previous work, rigid body models have been used to analyze such systems. There are two fundamental problems with such an approach. Firstly, the use of frictional laws, such as Coulomb's law, introduce inconsistencies and ambiguitie...