Using an Olami-Feder-Christensen model with velocity weakened friction and variable stress transfer range to model slip-stick behavior in a sheared granular fault gouge system*

We present a variant of the Olami-Feder-Christensen (OFC) model with variable stress transfer range and a residual stress modified according to a velocity weakened friction force. The model displays dynamical modes similar to those observed in a sheared granular fault gouge laboratory system. For long stress transfer ranges, we find dynamical phases including a steady sliding state, a stick-slip state with periodic system-wide slipping events, and an intermittent state with both steady sliding and occasional slipping. For medium stress transfer ranges, we find additionally intermediate phases with large slipping events occurring in localized patches of the system. We compare simulation results of the model to laboratory results for the sheared granular fault gauge system.