A refined incremental homogenization approach for heterogeneous nonlinear geomaterials without isotropization

This study presents a refined incremental homogenization (RIH) framework for predicting the macroscopic nonlinear mechanical behavior of heterogeneous geomaterials composed of inelastic constituents. The proposed approach builds upon the classical Hill incremental (CHI) method while incorporating the reference elastic medium (REM) concept to enhance computational efficiency. A key advantage of the RIH approach is its ability to bypass isotropization procedures, thereby providing a more consistent and physically representative homogenization scheme for inelastic geomaterials. The approach is applied to various geomaterials characterized by a continuous matrix (either elastoplastic or elastoplastic porous) embedded with spherical inclusions (elastic or elastoplastic-damage) or pores. The predictive capability of the RIH approach is assessed through comparisons with full-field finite element (FE) simulations under conventional triaxial compression loading conditions, demonstrating its accuracy in capturing the nonlinear mechanical response. Furthermore, the model’s effectiveness is validated by comparing its predictions with experimental data on Callovo-Oxfordian (COx) argillite with varying mineral compositions. These results highlight the robustness and efficiency of the proposed homogenization framework, making it a valuable tool for modeling the macroscopic behavior of complex geomaterials with inelastic heterogeneities.