Prediction of durability of a fiber bundle under uniaxial tension on the basis of the thermal fluctuation model of their brittle destruction

A model is proposed for assessing the durability of a bundle of identical fibers under conditions of brittle fracture in the region of tensile stresses located to the left of the Griffiths fracture threshold. It is shown that in the specified stress range, the average durability and the dispersion of durability values increase indefinitely with decreasing tensile stress. Estimates were obtained for the incubation period of durability, its confidence probability and the lower limit of the number of elements of a bundle of identical fibers that guarantee the required durability of the bundle.