Kinetic Friction of Ice

Séminaire de Erland Schulson (Hanover, NH, USA), mercredi 25 septembre à 14h, salle Lliboutry, bât de Glaciologie

Title : Kinetic Friction of Ice

Abstract :
The sliding of ice upon ice is a fundamental process in ice mechanics, from extraterrestrial icy satellites to terrestrial sea ice covers. At root is the interaction of asperities that protrude from opposing faces. In this talk I will review the effect of sliding velocity on the coefficient of kinetic friction of ice sliding over itself at low velocity. At very low velocities, the coefficient is governed by creep deformation. At higher velocities, ice melts and this leads to “velocity weakening”, where the coefficient decreases with increasing speed. The latter behavior, I interpret, as the result of a progressive increase in the number of contacts that have melted through frictional heating, the smallest ones melting at the onset of weakening and the largest at the end of the regime. The distribution of contact areas, I describe, in a fractal manner.

By Erland M. Schulson
Ice Research Laboratory
Thayer School of Engineering, Dartmouth College,
Hanover, New Hampshire, USA

Séminaire animé par Maurine Montagnat