Fluidization of wet granulates under shear

S. H. Ebrahimnazhad Rahbari, Jörg Vollmer, Stephan Herminghaus, Martin Brinkmann

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

Small amounts of a wetting liquid render sand a stiff and moldable material. The cohesive forces between the sand grains are caused by capillary bridges at the points of contact. Due to the finite strength of these bridges wet sand undergoes a transition from an arrested (i.e., solidified) to a fluidized state under an externally applied shear force. The transition between these two dynamic states is studied in a MD-type simulation of a two-dimensional assembly of bidisperse frictionless disks under the action of a cosine force profile. In addition to soft core repulsion the disks interact through a hysteretic and short ranged attractive force modeling the effect of the capillary bridges. In this model the transition between the fluidized and the arrested state is discontinuous and hysteretic. The parameter dependence of the critical force for solidification is modeled by combining theoretical arguments with a detailed numerical exploration of the transition. We address a range of densities from slightly below close packing until slightly above densities where the system approaches a shear-banded state. Differences and similarities of the transition in wet granulates to the jamming transition are also addressed.
Original languageEnglish
Article number061305
JournalPhysical Review E
Volume82
Issue number6
DOIs
Publication statusPublished - 16 Dec 2010
Externally publishedYes

Cite this