Static Friction Coefficient Is Not a Material Constant
Oded Ben-David and Jay Fineberg
The Racah
Institute of Physics, The Hebrew University of Jerusalem,
Jerusalem 91904, Israel
(Received 28 April 2011; published 20 June 2011)
The static friction coefficient
between two materials is considered to be a material constant. We present
experiments demonstrating that the ratio of
shear to normal force needed to move contacting bodies can,
instead, vary systematically with
controllable changes in the external loading configuration.
Large
variations in both the friction coefficient and consequent stress drop are tightly
linked to changes in
the rupture dynamics of the rough
interface separating the two bodies.
DOI: 10.1103/PhysRevLett.106.254301 PACS numbers: 46.55.+d, 46.50.+a, 62.20.Qp, 81.40.Pq