Multiyield-Surface Implementation of a Simplified Three-Dimensional Hoek-Brown Strength Criterion

This work presents the implementation of a simplified three-dimensional Hoek-Brown strength criterion using a multiyield-surface plasticity approach. The adopted three-dimensional simplification of the strength criterion accounts for the intermediate principal stress influence, maintaining the simplicity in the numerical implementation. This criterion corresponds to a paraboloid surface of circular cross section in the principal stress space. The introduction of multiple yield surfaces allows for a smooth definition of the nonlinear stress-strain behavior of the material. In addition, a kinematic hardening rule is adopted, allowing yield surfaces to translate with loading, enabling a hysteretic and path-dependent stress-strain response.

Automated summary

This work presents the implementation of a simplified three-dimensional Hoek-Brown strength criterion using a multiyield-surface plasticity approach. The adopted three-dimensional simplification takes into account the influence of the intermediate principal stress and maintains simplicity in numerical implementation. The introduction of multiple yield surfaces allows for a smooth definition of the material's nonlinear stress-strain behavior, while a kinematic hardening rule enables a hysteretic and path-dependent stress-strain response.