The long-term strength of optical fibers under conditions of ageing of the material

The long-term cracking resistance of an optical fiber has been studied in terms of the nonlinear fracture mechanics. The ageing of the material due to internal and external factors such as humidity and temperature is taken into account. Based on the experimental data, the deformation of an optical fiber is described by the Volterra second-kind integral operators. The theoretical approach proposed is in good agreement with the experimental data and allows one to reliably predict the service life of an optical fiber under operating conditions from the results of a reference experiment on the long-term strength.