Details

Autor(en) / Beteiligte

• Clark, Abram H
• Petersen, Alec J
• Kondic, Lou
• Behringer, Robert P

Titel

Nonlinear force propagation during granular impact

Ist Teil von

• Physical review letters, 2015-04, Vol.114 (14), p.144502-144502, Article 144502

Ort / Verlag

United States

Erscheinungsjahr

2015

Quelle

PROLA

Beschreibungen/Notizen

• We experimentally study nonlinear force propagation into granular material during impact from an intruder, and we explain our observations in terms of the nonlinear grain-scale force relation. Using high-speed video and photoelastic particles, we determine the speed and spatial structure of the force response just after impact. We show that these quantities depend on a dimensionless parameter, M^{'}=t_{c}v_{0}/d, where v_{0} is the intruder speed at impact, d is the particle diameter, and t_{c} is the collision time for a pair of grains impacting at relative speed v_{0}. The experiments access a large range of M^{'} by using particles of three different materials. When M^{'}≪1, force propagation is chainlike with a speed, v_{f}, satisfying v_{f}∝d/t_{c}. For larger M^{'}, the force response becomes spatially dense and the force propagation speed departs from v_{f}∝d/t_{c}, corresponding to collective stiffening of a strongly compressed packing of grains.