title: Unjamming of granular packings due to local perturbations: stability and decay of displacements.
abstract: We study the mechanical response generated by local deformations in jammed packings of rigid disks. Based on discrete element simulations we determine the critical force of the local perturbation that is needed to break the mechanical equilibrium and examine the generated displacement field. Displacements decay as a power law of the distance from the perturbation point. The decay exponent and the critical force exhibit a nontrivial dependence on the friction: Both quantities are nonmonotonic and have a sharp maximum at the friction coefficient 0.1. We find that the mechanical response properties are closely related to the problem of force indeterminate where similar nonmonotonic behavior was observed previously. We establish a direct connection between the critical force and the ensemble of static force networks.
authors.affiliation: Department of Theoretical Physics, Budapest University of Technology and Economy, H-1111 Budapest, Hungary.
authors.forename: M
authors.initials: M
authors.lastname: Reza Shaebani
authors.forename: Tamás
authors.initials: T
authors.lastname: Unger
authors.forename: János
authors.initials: J
authors.lastname: Kertész