Slip avalanches in a fiber bundle model

Department of Theoretical Physics, University of Debrecen - H-4010 Debrecen, P.O. Box 5, Hungary, EU

Corresponding author: feri@dtp.atomki.hu

Received: 17 September 2009
Accepted: 8 January 2010

Abstract

We study slip avalanches in disordered materials under an increasing external load in the framework of a fiber bundle model. Overstressed fibers of the model do not break, instead they relax in a stick-slip event which may trigger an entire slip avalanche. Slip avalanches are characterized by the number of slipping fibers, by the slip length, and by the load increment, which triggers the avalanche. Our calculations revealed that all three quantities are characterized by power law distributions with universal exponents. We show by analytical calculations and computer simulations that varying the amount of disorder of slip thresholds and the number of allowed slips of fibers, the system exhibits a disorder-induced phase transition from a phase where only small avalanches are formed to another one where a macroscopic slip appeares.