New high-speed experiment capability for study of friction Conference Paper uri icon

abstract

  • Copyright 2015 ARMA, American Rock Mechanics Association. Recent experimental investigations of friction in rock demonstrate pronounced reduction in the apparent coefficient of friction at seismic slip rates (>0.1 m/s). Here we present the capabilities of a novel apparatus under development that can accommodate both double-direct and triaxial shear configurations to investigate friction at low to high-speed (up to 2 m/s) sliding conditions. The high acceleration capability of the loading-system is complementary to other high-speed testing machines, and is particularly well suited for study of rate-dependence of friction at high normal stress and of transient behavior associated with dynamic weakening. Preliminary friction experiments at normal stress of approximately 5 MPa have been conducted to investigate transient friction associated with slip velocity steps from low to high speed sliding (>0.5 m/s). Results show that, independent of surface roughness, friction increases concurrently with a step increase to high velocity and then decreases with slip consistent with the direct and evolution effects documented for rate-state friction behavior at quasi-static slip rates. Friction during sustained highspeed sliding is characterized by a steady and substantial weakening that likely reflects the accumulation of fine wear product along the surfaces.

published proceedings

  • 49th US Rock Mechanics / Geomechanics Symposium 2015

author list (cited authors)

  • Saber, O., Chester, F. M., & Alvarado, J. L

complete list of authors

  • Saber, O||Chester, FM||Alvarado, JL

publication date

  • January 2015