Torsional strength of a transversally isotropic cylinder containing a system of healed cracks

The strength of a transversally isotropic cylinder with a system of healed torsional cracks is investigated in this paper. Degradation of service characteristics of the reinforced-concrete materials in APP structures, mine shaft s, collectors, and hydraulic works delved into the necessity of serviceability renewal, repair, and the restoration of carrying ability in such structural elements. A mathematical model has been developed to evaluate the effect of cylinder strengthening using injection technologies for healing defects. The calculations are based on the concepts of fracture mechanics and linear theory of elasticity. The model of thin elastic inclusions and the theory of harmonic functions are applied, which enables reduction to the problem of solving a system of integral equations. The parameters that affect the efficiency of crack healing are identified. Analytical solutions for particular cases were obtained, which allowed for optimizing the choice of injection material. It is shown that the correct selection of the injection material stiff ness can ensure the complete restoration of the strength of a cracked cylinder.