Identification of friction vibration interaction between solids

Abstract EN

Dry-friction forces have been shown to depend not only on the characteristics of the surface in con-tact but also on the dynamic interaction of the contacting bodies.

A viscoelastic mathematical model that accounts for the interaction at micro-scale of rough surfaces is developed.

The mathematical formulation relates the tribological events at microscopic and macroscopic scales vibration response of a "mass on moving belt".

The viscoelastic properties are presented by combining loss modulus with Young's modulus to obtain a differential operator on the interference, reminiscent of the Kelvin-Voigt model.

The analysis of the system establishes the relation between friction force and speed and supports observed behavior of many systems with friction.

The derivations do not rely on a phenomenological account of friction, which requires a presumed friction coefficient.

Instead the friction force is accounted for as a result of interaction of the rough surfaces.

This has led to a set of nonlinear ordinary differential equations that directly relate the vibration of the system to the surface parameters.

It is shown that, as a result of coupling of the macro system's dynamics and contact, there are combinations of parameters at micro- and macro scale that yield negative slope in friction force / sliding speed relation, a well known source of dynamic instability.