A new interparticle friction apparatus for granular materials

I. Cavarretta, Irene Rocchi, M. R. Coop

Research output: Contribution to journalJournal articleResearchpeer-review


A new apparatus is described that measures interparticle friction between sand-sized grains over relatively large displacements and also under immersion in a fluid. Its relatively simple design allows the key calibrations to be checked by statics. An analysis of the geometry of simple spherical particle contacts and the forces at those contacts revealed that there are strict constraints on the permissible stiffness of the interparticle friction apparatus to avoid stick-slip behaviour. Tests on ball bearings gave highly repeatable data, while others on glass ballotini revealed a significant effect of ambient humidity on the data obtained. The interparticle friction was found to increase with the roughness of the ballotini. Immersion in water increased the interparticle friction slightly for both the ballotini and quartz sand particles, while immersion in oil reduced the friction considerably for the quartz sand, especially at higher contact force levels.
Original languageEnglish
JournalCanadian Geotechnical Journal
Issue number12
Pages (from-to)1829-1840
Number of pages12
Publication statusPublished - 2011
Externally publishedYes


  • Friction
  • Nonconforming contact
  • Yield surface
  • Calibration
  • Stiffness


Dive into the research topics of 'A new interparticle friction apparatus for granular materials'. Together they form a unique fingerprint.

Cite this