Time evolution of damage in thermally induced creep rupture
Department of Theoretical Physics, University of Debrecen - H-4010 Debrecen, P.O. Box 5, Hungary, EU
2 Yukawa Institute for Theoretical Physics, Kyoto University - Kitashirakawa Oiwake-cho, 606-8502 Kyoto, Japan
3 Department of Applied Physics, Graduate School of Engineering, The University of Tokyo 7-3-1, Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan
Accepted: 9 December 2011
We investigate the time evolution of a bundle of fibers subject to a constant external load. Breaking events are initiated by thermally induced stress fluctuations followed by load redistribution which subsequently leads to an avalanche of breakings. We compare analytic results obtained in the mean-field limit to the computer simulations of localized load redistribution to reveal the effect of the range of interaction on the time evolution. Focusing on the waiting times between consecutive bursts we show that the time evolution has two distinct forms: at high load values the breaking process continuously accelerates towards macroscopic failure, however, for low loads and high enough temperatures the acceleration is preceded by a slow-down. Analyzing the structural entropy and the location of consecutive bursts we show that in the presence of stress concentration the early acceleration is the consequence of damage localization. The distribution of waiting times has a power law form with an exponent switching between 1 and 2 as the load and temperature are varied.
PACS: 62.20.M- – Structural failure of materials / 02.50.-r – Probability theory, stochastic processes, and statistics / 05.90.+m – Other topics in statistical physics, thermodynamics, and nonlinear dynamical systems (restricted to new topics in section 05)
© EPLA, 2012