Out-of-plane principal stress in plane strain/stress failure investigations – an overview of its relevance for various failure criteria

Abstract

The paper exposes the role of the out-of-plane principal stress in the investigations of (brittle) failure of isotropic linear elastic continuum using plane strain (or plane stress) approximations. The plots in (σ_m, τ_m), (σ₃, σ₁) spaces for each of the examined criteria: the two-dimensional: Coulomb, Tresca, Hoek-Brown, and the three-dimensional ones: Drucker-Prager and linear Mogi, give an insight into the interplay of Poisson ratio and the material parameters involved in the respective criterion formula.