title: Static friction coefficient is not a material constant.
abstract: 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.
authors.affiliation: The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Oded
authors.initials: O
authors.lastname: Ben-David
authors.forename: Jay
authors.initials: J
authors.lastname: Fineberg