On The Influence of a Non-Classical Diffusion Process on the Long-Term Fracture of a Composite Tensile Rod During Creep

Abstract

The stress-strain state is considered and the time to fracture of a composite tensile rod during creep in an active medium is determined. The influence of the active medium is determined by a non-classical diffusion process, with the active substance penetrating into the material in two states: free and bound. The process of such diffusion is described by a modified diffusion equation that takes into account the two-phase state of the active substance in the material. A system of equations has been obtained that models the creep of a composite rod, in which its parts are rigidly connected to each other without slipping, and also includes kinetic equations for the accumulation of damage in parts of the rod. The influence of the active medium is taken into account by introducing into the indicated kinetic equations the function of the influence of the active medium - a function of the integral average concentration. Stress distributions and damage accumulation processes over time in various parts of the composite rod are analyzed. Calculations were carried out in two cases, namely, classical and non-classical diffusion processes are considered. The setting of these differences is determined by the choice of appropriate parameters in the diffusion model under consideration. Dependences of damage accumulation and stress distribution in parts of the rod over time were obtained.

As a result, it was determined that the destruction of a composite rod in the classical case occurs earlier than in the case of the considered non-classical diffusion process.