In this paper, validation of a model for the speed dependency of friction is presented. Based on the shape of the friction – speed curve, the model assumes that calculation of friction at any speed would need an estimate of friction at very low speed, and the knowledge of its variation with speed described by the Stribeck curve. Two existing models developed at LCPC are then coupled to predict ...

OBJECTIVE The aim of this study was to compare the friction between three bracket models: conventional stainless steel (Ovation, Dentsply GAC), self-ligating ceramic (In-Ovation, Denstply GAC) and self-ligating stainless steel brackets (In-Ovation R, Dentsply GAC). METHODS Five brackets were used for each model. They were bonded to an aluminum prototype that allowed the simulation of four mis...

We present a simple model for the friction of two solid bodies moving against each other. In a self consistent way we can obtain the dependence of the macroscopic friction force as a function of the driving velocity, the normal force and the ruggedness of the surfaces in contact. Our results are discussed in the context of friction laws used in earthquake models. PACS numbers: 46.30.Pa 81.40.Pa...

Free and forced oscillations of a torsion spring pendulum damped by viscous and dry (Coulomb) friction are investigated analytically and with the help of computer simulations. An idealized mathematical model of dry friction described by the so-called z-characteristic is assumed. This simple physical model can explain many peculiarities in behavior of various oscillatory systems with dry frictio...

Finite element analysis based techniques are available to simulate cutting processes and offer several advantages including prediction of tool forces, distribution of stresses and temperatures, estimation of tool wear and residual stresses on machined surfaces, optimization of cutting tool geometry and cutting conditions. However, work material flow stress and friction characteristics at cuttin...

We simulate dynamic ruptures on a strike-slip fault in homogeneous and layered half-spaces and on a thrust fault in a layered half-space. With traditional friction models, sliding friction exceeds 50% of the fault normal compressive stress, and unless the pore pressures approach the lithostatic stress, the rupture characteristics depend strongly on the depth, and sliding generates large amounts...

In this paper a complete 3D contact model is presented. This model has nonlinearity in determining both normal and friction forces. A new nonlinear normal force model is introduced and the differences between this new model and previous ones are described. Also, the characteristics of this model are discussed and compared with the classical models and empirical results. For calculating the fric...

Lateral Force Microscopy (LFM) studies were carried out on cleaved calcite sections in contact with solutions supersaturated with respect to otavite (CdCO3) or calcite-otavite solid solutions (SS) as a means to examine the potential for future application of LFM as a nanometer-scale mineral surface composition mapping technique. Layer-by-layer growth of surface films took place either by step a...

We investigate the velocity dependence of kinetic friction with a model that makes minimal assumptions on the actual mechanism of friction so that it can be applied at many scales, provided the system involves multicontact friction. Using a recently developed master equation approach, we investigate the influence of two concurrent processes. First, at a nonzero temperature, thermal fluctuations...

With nanotextured surfaces and interfaces increasingly being encountered in technological and biomedical applications, there is a need for a better understanding of frictional properties involving such surfaces. Here we report friction measurements of several nanostructured surfaces using an Atomic Force Microscope (AFM). These nanostructured surfaces provide well defined model systems on which...