The application of a dual relay feedback approach towards the identification of frictional effects in servo-mechanisms will be presented in this paper. The friction model, thus identified, will consist of Coulomb (including possibly directional Coulomb or load bias) and viscous friction components, both of which can be automatically extracted from suitably designed relay experiments. At the sam...

This paper presents a method for estimating Coulomb and viscous friction coefficients from responses of a harmonically excited dual-damped oscillator with linear stiffness. The identification method is based on existing analytical solutions of non-sticking responses excited near resonance. The method is applicable if the damping ratio of viscous component can be considered small. The Coulomb an...

The simulation of granular particles in a quasi-two-dimensional container under vertical vibration as an experimental accessible model for granular gases is performed. The velocity distribution function obeys an exponential-like function during the vibration and deviates from the exponential function in free-cooling states. It is confirmed that this exponentiallike distribution function is prod...

Analysis and theoretical comparison between several fixed point strategies and Uzawa algorithms (for classical and augmented Lagrangian) are performed to solve the so called Signorini problem with Coulomb friction without any regularization. Thanks to a formalism coming from convex analysis, some new fixed point strategies are presented and compared to already known methods. The analysis is fir...

The dry frictional contact between two solid surfaces is well known to obey Coulomb friction laws. In particular, the static friction force resisting the relative lateral (tangential) motion of solid surfaces, initially at rest, is known to be proportional to the normal force and independent of the area of the macroscopic surfaces in contact. Experimentally, the static friction force has been o...

We propose a Langevin model with Coulomb friction. Through the analysis of the corresponding Fokker-Planck equation, we have obtained the steady velocity distribution function under the influence of the external field.

This paper analyses the problem of modelling joint friction in robotic manipulators with gear transmissions at joint velocities varying from close to zero until their maximum appearing values. It is shown that commonly used friction models that incorporate Coulomb, (linear) viscous and Stribeck components are inadequate to describe the friction behaviour for the full velocity range. A new frict...

Large strains, anisotropy of mechanical properties of materials and Coulomb friction in contact regions are some properties in the analysis of deep drawing process. In this research, the effects of different parameters such as anisotropy coefficient, work hardening exponent and friction coefficient on deep drawing process of drawing quality steel are studied. For this purpose, the finite elemen...

Friction, which evidently appears in any mechanical systems incorporating parts with relative motion, manifests itself as material nonlinearity. Depending on its application, friction can be a desirable thing or a drawback in the system. In order to optimally utilize or compensate for the frictional effect in a system, characterization of the frictional behaviour is very crucial. The classical ...

The behavior of marine-terminating ice sheets, such as the West Antarctic ice sheet, is of interest due to the possibility of rapid grounding-line retreat and consequent catastrophic loss of ice. Critical to modeling this behavior is a choice of basal rheology, where the most popular approach is to relate the ice-sheet velocity to a power-law function of basal stress. Recent experiments, howeve...