title: Onset of sliding in amorphous films triggered by high-frequency oscillatory shear.
abstract: We investigate the change of the static friction threshold of weakly adhesive amorphous interfaces in the presence of the shear ultrasonic oscillation. Prior to sliding, a softening of the shear interfacial stiffness is observed under either static or high-amplitude oscillatory shear. We find that the nonlinear shear ultrasound, regardless of its polarization, triggers the macroscopic sliding at these interfaces far below the static threshold. Such unjamming transition is due to the vibration-induced decrease of the apparent coefficient of static friction, which provides a mechanism for understanding the reduction of the yielding threshold of granular media by the acoustic fluidization.
authors.affiliation: Université Paris Est, LPMDI, 5 Bd Descartes, 77454 Marne-la-Vallée Cedex 2, France.
authors.forename: J
authors.initials: J
authors.lastname: Léopoldès
authors.affiliation: Université Paris Est, LPMDI, 5 Bd Descartes, 77454 Marne-la-Vallée Cedex 2, France.
authors.forename: G
authors.initials: G
authors.lastname: Conrad
authors.affiliation: Université Paris Est, LPMDI, 5 Bd Descartes, 77454 Marne-la-Vallée Cedex 2, France and Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, 1 rue Jussieu 75005 Paris, France.
authors.forename: X
authors.initials: X
authors.lastname: Jia