Jamming in systems with quenched disorder

Abstract

We numerically study the effect of adding quenched disorder in the form of randomly placed pinning sites on jamming transitions in a disk packing that jams at a well defined point J in the clean limit. Quenched disorder decreases the jamming density and introduces a depinning threshold. The onset of a finite threshold coincides with point J at the lowest pinning densities, but for higher pinning densities there is always a finite depinning threshold even well below jamming. We find that proximity to point J strongly affects the transport curves and noise fluctuations, and observe a change from plastic behavior below jamming, where the system is highly heterogeneous, to elastic depinning above jamming. Many of the general features we find are related to other systems containing quenched disorder, including the peak effect observed in vortex systems.

Pinning Susceptibility: The Effect of Dilute, Quenched Disorder on Jamming

“…Increasing n f raises the probability of jamming at any given value of φ, in accord with previous work on jamming in the presence of fixed particles [5,6]. Increasing N steepens the jamming probability, as in the absence of pinning [11].…”

Geometry dependence of the clogging transition in tilted hoppers

“…The sudden formation of a stable arch over the exit halts all flow, and then the entire system is jammed. Other systems which demonstrate clogging include the flow of vortices through an array of pinning sites in type II superconductors as well as grains flowing through an array of obstacles [17][18][19]. These systems demonstrate a clogging transition which depends on the density of pinning sites and the packing fraction of particles.…”

Fraction of Clogging Configurations Sampled by Granular Hopper Flow

“…Furthermore, clogging is a natural phenomenon that illustrates spontaneous evolution from a freely-flowing state to a jammed state with no change in the external forcing. Similar issues are important for understanding the flow of suspensions [4][5][6] through constrictions, the flow of vortices through an array of pinning sites in superconductors [7,8], as well as automotive [9] and pedestrian [10] traffic. In spite of many simulations [11][12][13][14] and experiments in both two- [1,[15][16][17][18][19] and three-dimensional hoppers [2,3,12,[20][21][22][23], the ability to predict or control clogging is still lacking [24].…”