A general control scheme to control flexible arms with friction in the joints is proposed in this paper. This scheme presents the advantage of being robust in the sense that it minimizes the effects of the Coulomb friction existing in the motor and the effects of changes in the dynamic friction coefficient. A justification of the robustness properties of the scheme is given in terms of the sens...

This paper analyzes a discrete form of 3D contact problems with local orthotropic Coulomb friction and coefficients of friction which may depend on the solution itself. The analysis is based on the fixed-point reformulation of the original problem. Conditions guaranteeing the existence and uniqueness of discrete solutions are established. Finally, numerical results of a model example are presen...

Being a complex nonlinear phenomenon, friction is a difficult part to characterize and identify in a mechanical system. Friction is the result of interaction between one body over or along another and is dependent on many parameters, such as contact geometry, topography, surface materials, presence and type of lubrication and relative motion. The classical Coulomb friction has been widely used ...

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. ...

We investigate the free cooling of inelastic rough spheres in the presence of Coulomb friction. Depending on the coefficients of normal restitution ǫ and Coulomb friction μ, we find qualitatively different asymptotic states. For nearly complete normal restitution (ǫ close to 1) and large μ, friction does not change the cooling properties qualitatively compared to a constant coefficient of tange...

We use a complementarity approach to pose the Coulomb friction model, combine it with a non-penetration condition, and append to a differential algebraic problem to characterize the dynamics of multibody systems with friction and contact. The resulting problem is relaxed to a Cone Complementarity Problem, whose solution is shown to represent the first order optimality condition of a quadratic p...

The generation of higher harmonics of the magnetoplasmon frequency which has recently been reported in strongly coupled two-dimensional Yukawa systems is investigated in detail and, in addition, extended to two-dimensional Coulomb systems. We observe higher harmonics over a much larger frequency range than before and compare the theoretical prediction with the simulations. The influence of the ...

This work identifies damping parameters from compliantcontact vibration systems using energy dissipation concept. To develop the identification algorithms, the energy loss as registered in the force-displacement relationship of the real system is balanced against that of a theoretical model incorporating with an idealized compliant contact. Two approaches, including one based on the harmonic re...

-We describe slip-rate dependent friction laws based on the Coulomb failure criteria. Frictional rate dependence is attributed to a rate dependence of cohesion c and friction angle qS. We show that differences in the stress states developed during sliding result in different Coulomb friction taws for distributed shear within a thick gouge layer versus localized shear within a narrow shear band ...