Multiscale modeling and characterization of coupled damage-healing-plasticity for granular materials in concurrent computational homogenization approach

The proposed modeling and characterization method for coupled damage-healing-plasticity in granular material is comprised of the following three constituents. The incremental non-linear constitutive relation for the discrete particle assembly of RVE is first established. Then the meso-mechanically informed incremental non-linear constitutive relation of macroscopic gradient-enhanced Cosserat continuum is derived from volume averages of the RVE-scale solutions. Finally the thermodynamic framework is set up to define meso-mechanically informed anisotropic damage and healing factors, anisotropic net damage factors combining both damage and healing effects, and plastic strains. Densities of damage, plastic and total dissipative energies as well as non-dissipative healing energy, as scalar internal state variables, are provided to compare the effects of damage, healing and plasticity on material failure and structural collapse. The numerical example of strain localization and softening problem is performed to demonstrate the performance and applicability of the proposed multiscale modeling and characterization method of coupled damage-healing-plasticity for granular materials.