title: Loading-unloading of an elastic-plastic adhesive spherical microcontact.
abstract: A numerical solution is presented for a single load-unload cycle of an adhesive contact between an elastic-plastic sphere and a rigid flat. The interacting forces between the sphere and the flat are obtained through connecting nonlinear spring elements having force-displacement behavior that obeys the Lennard-Jones potential. Kinematic, rather than isotropic, hardening is assumed for the sphere material to account for possible secondary plastification during the unloading. The well-known Tabor parameter and a plasticity parameter are shown to be the two main dimensionless parameters governing the problem. The effects of these two parameters on the load-approach curves, on the plastically deformed sphere profiles, and on the plastic strain fields inside the sphere are presented, showing different modes of separation during the unloading.
authors.affiliation: Department of Mechanical Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Kadin
authors.forename: Y
authors.initials: Y
authors.lastname: Kligerman
authors.forename: I
authors.initials: I
authors.lastname: Etsion