ABSTRACT
This work presents an analytical micromechanical model for quasi-brittle materials featuring coupled, direction-dependent friction and cohesion. Building on mean-field homogenization, the formulation addresses key limitations of existing models by introducing an implicit solution procedure and an energy-based damage law based on a total, rather than partial free energy derivative. Along with a newly proposed damage resistance function ensuring linear softening under tension, the model captures complex emergent behaviors from a simple set of parameters. Numerical examples show that hardening under compression, anisotropic crack evolution, and confinement strengthening effects are all qualitatively reproduced from the prescribed tensile behavior without any additional parameters. They also demonstrate the model’s ability to handle complex stress-states in a stable and physically meaningful way.
