203 citations · 684 across the 18 of their papers we have counts for
19 papers
Rapid generation of relaxed centimeter-sized drops by capillary auto-ejection
Patric Mueller, Kai Ihrig, Achim Sack +2
Many microgravity experiments require centimeter-sized spherical liquid drops. In drop-tower experiments, only a few seconds of microgravity are available, so the drops must be gen…
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…
The growth of super-large pre-planetary pebbles to an impact erosion limit
J. Teiser, J. Penner, K. Joeris +4
Early dust evolution in protoplanetary disks is dominated by sticking collisions. However, this initial phase of particle growth faces constraints - notably from destructive encoun…
Ultra Low Velocity Ejecta Generated by Slow Impacts on Rubble Pile Asteroids
Kolja Joeris, Laurent Schönau, Matthias Keulen +1
We examine ejecta generated by ultra low velocity impacts under asteroid conditions. In an environment of precisely controlled milligravity and under vacuum, impacts with velocitie…
Controlled Partial Gravity Platform for Milligravity in Drop Tower Experiments
Kolja Joeris, Matthias Keulen, Jonathan E. Kollmer
We detail a platform for partial g environment and an experiment for simulated impacts on asteroid surfaces based on it. The partial g environment is created by a two stage approac…
Thermal Creep on Mars: Visualizing a Soil Layer under Tension
Tetyana Bila, Jonathan Kollmer, Jens Teiser +1
At low ambient pressure, temperature gradients in porous soil lead to a gas flow, called thermal creep. With this regard, Mars is a unique as the conditions for thermal creep to oc…
Experimental study of clusters in dense granular gas and implications for the particle stopping time in protoplanetary disks
Niclas Schneider, Grzegorz Musiolik, Jonathan E. Kollmer +6
In protoplanetary disks, zones of dense particle configuration promote planet formation. Solid particles in dense clouds alter their motion through collective effects and back reac…
Stick-slip dynamics in penetration experiments on simulated regolith
Jack Featherstone, Robert Bullard, Tristan Emm +7
The surfaces of many planetary bodies, including asteroids and small moons, are covered with dust to pebble-sized regolith held weakly to the surface by gravity and contact forces.…
Laboratory Impact Splash Experiments to Simulate Asteroid Surfaces
Tabea Bogdan, Jonathan E. Kollmer, Jens Teiser +2
Granular material that is bound by the low gravity of a small asteroid is mobilized by slow velocity impacts. These splashes generated by impacts might play an important role in sc…
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…
ARISE: A granular matter experiment on the International Space Station
Tobias Steinpilz, Grzegorz Musiolik, Maximilian Kruss +8
We developed an experiment to study different aspects of granular matter under microgravity. The 1.5U small experiment was carried out on the International Space Station. About 350…
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…