Lecturer: Prof. Jay Fineberg
Affiliation: Racah Institute of Physics,
The Hebrew University of Jerusalem
Abstract:
Friction is generally described by a single
degree of freedom, a ‘friction coefficient’. We
experimentally study the space-time dynamics
of the onset of dry and lubricated frictional
motion when two contacting bodies start to
slide. We first show that the transition from
static to dynamic sliding is governed by
earthquakes. Moreover, the structure of both
these "laboratory earthquakes" as well as the
real thing is quantitatively described by
singular solutions describing the motion of
rapid cracks. We demonstrate that this
framework quantitatively describes both
earthquake motion and arrest. A further
surprise is that lubricated interfaces, although
“slippery”, actually becomes tougher;
lubricants significantly increase dissipated
energy during rupture. The results establish a
new (and fruitful) paradigm for describing
friction.