Tensor models of rupture strengh. Report no. 1. Steady loading of initially isotropic and anisotropic bodies

A relationship is established between the rupture-strength theory of Il'yushin and the Pisarenko—Lebedev criterion. The variant proposed for constructing tensor models of rupture strength is based on prior knowledge of the rupture-strength surface — the dependence of the time to fracture under steady loading on stress intensity and other dimensionless invariants of the stress state. This condition makes it possible to reduce the damage tensor to a deviator, so that simpler criterional relations follow from the model. The rupture-strength surfaces of certain steels and alloys are constructed from well-known experimental data obtained for a plane stress state. Tensor models for bodies with initial rupture-strength anisotropy are also constructed. Satisfactory agreement is obtained between theoretical and experimental data on the tension of single crystals of a nickel alloy with an fcc lattice.Translated from Problem Prochnosti, No. 8, pp. 76–80, August, 1995.