Disorder enhances the effects of thermal noise in the fiber bundle model

The statistical properties of failure are studied in a ber bundle model with thermal noise. We show that the macroscopic failure is produced by a thermal activation of microcracks. Most importantly, the effective temperature of the system is amplified by the spatial disorder (heterogeneity) of the ber bundle. These results give new insight to the study of thermally activated cracks and they can be useful in the study of electrical networks.