An advanced constitutive model for transversely isotropic rock - Evaluation of two different regularization approaches

Abstract The mathematical description of the material behavior rock is a demanding task in engineering practice. Rock classified as frictional cohesive characterized by highly nonlinear mechanical with irreversible deformation, strain hardening, softening and degradation stiffness. In addition, depending on origin particular type, orientation minerals grains well formation stratification planes lead to inherent anisotropic behavior. Especially stratified types like shales or phyllites, often special case transversely isotropic encountered. previous work, novel continuum-based model for describing both, rock, denoted TI-RDP model, was presented. By means linear mapping Cauchy stress tensor into fictitious configuration, an established damage plasticity extended. this contribution two different regularization approaches, which are models, i.e., mesh-adjusted modulus implicit gradient-enhancement, adopted model. Based uniaxial tension triaxial compression tests considering orientations principal directions respect direction axial loading, their capabilities assessed terms predicting direction-dependent mesh-insensitive manner.