Thermal activation of rupture and slow crack growth in a model of homogeneous brittle materials

Abstract

Slow crack growth in a model of homogenous brittle elastic material is\ndescribed as a thermal activation process where stress fluctuations allow to\novercome a breaking threshold through a series of irreversible steps. We study\nthe case of a single crack in a flat sheet for which analytical predictions can\nbe made, and compare them with results from the equivalent problem of a 2D\nspring network. Good statistical agreement is obtained for the crack growth\nprofile and final rupture time. The specific scaling of the energy barrier with\nstress intensity factor appears as a consequence of irreversibility. In\naddition, the model brings out a characteristic growth length whose physical\nmeaning could be tested experimentally.\n