Dyachenkо А.А., Shushpanov О.Е.
The new thermodynamic model of silica fibres failure is developed. The model is based on the exponential dependence of microcracks speed growth on tension loads. The equations for lifetime and dynamic strength of optical fibres giving the possibility for research of failure process under different temperatures, humidity and acidity of external medium are given. Phenomena of the surface microcracks healing by coating materials, the influence of process of glass dissolving in water as well as the degradation process of elasticity modulus of the healing materials on the optical fibres lifetime and their dynamic strength are taken into consideration. The calculated data of lifetime and dynamic strength of optical fibres are well agreed with the experimental data, received in a wide interval of tension load value and external space conditions