203 citations · 684 across the 18 of their papers we have counts for
10 papers · 1 filter
Granular clogging across gravities: a unified scaling
Oliver Gaida, Olfa D'Angelo, Jonathan E. Kollmer
Lacking a universal law for granular flows across gravitational environments, fundamental processes such as hopper discharge remain vulnerable to failure in low gravity environment…
Sponge-like rigid structures in frictional granular packings
Kuang Liu, Jonathan E. Kollmer, Karen E. Daniels +2
We show how rigidity emerges in experiments of sheared frictional granular materials by using generalizations of two methods for identifying rigid structures. Both approaches, the…
Enlightening force chains: a review of photoelasticimetry in granular matter
Aghil Abed Zadeh, Jonathan Barés, Theodore A. Brzinski +10
A photoelastic material will reveal its internal stresses when observed through polarizing filters. This eye-catching property has enlightened our understanding of granular materia…
Rigidity percolation control of the brittle-ductile transition in disordered networks
Estelle Berthier, Jonathan E. Kollmer, Silke E. Henkes +3
In ordinary solids, material disorder is known to increase the size of the process zone in which stress concentrates at the crack tip, causing a transition from localized to diffus…
Betweenness Centrality as Predictor for Forces in Granular Packings
Jonathan E. Kollmer, Karen E. Daniels
A load applied to a jammed frictional granular system will be localized into a network of force chains making inter-particle connections throughout the system. Because such systems…
Protocol-Dependence and State Variables in the Force-Moment Ensemble
Ephraim S. Bililign, Jonathan E. Kollmer, Karen E. Daniels
Stress-based ensembles incorporating temperature-like variables have been proposed as a route to an equation of state for granular materials. To test the efficacy of this approach,…
An experimental investigation of the force network ensemble
Jonathan E. Kollmer, Karen E. Daniels
We present an experiment in which a horizontal quasi-2D granular system with a fixed neighbor network is cyclically compressed and decompressed over 1000 cycles. We remove basal fr…
Photoelastic force measurements in granular materials
Karen E. Daniels, Jonathan E. Kollmer, James G. Puckett
Photoelastic techniques are used to make both qualitative and quantitative measurements of the forces within idealized granular materials. The method is based on placing a birefrin…
Energy Dissipation in Driven Granular Matter in the Absence of Gravity
Achim Sack, Michael Heckel, Jonathan E. Kollmer +2
We experimentally investigate the energy dissipation rate in sinusoidally driven boxes which are partly filled by granular material under conditions of weightlessness. We identify…
Movers and shakers: Granular damping in microgravity
Marcus N. Bannerman, Jonathan E. Kollmer, Achim Sack +3
The response of an oscillating granular damper to an initial perturbation is studied using experiments performed in microgravity and granular dynamics mulations. High-speed video a…