Homogenization of Cohesive-Frictional Strength Properties of Porous Composites: Linear Comparison Composite Approach

Abstract

This paper introduces a novel micromechanics method for strength homogenization of cohesive-frictional porous composites. Within a yield design formulation, the inherently nonlinear homogenization problem associated with strength upscaling is treated by the linear comparison composite (LCC) theory, which resolves the strength properties of the heterogeneous medium by estimating the effective properties of a suitable linear comparison composite with similar underlying microstructure. The LCC homogenization method rationalizes the development of strength criteria for cohesive-frictional materials affected by the presence of porosity and rigidlike inclusions. Modeling results for benchmark microstructures improve existing micromechanics formulations by allowing the consideration of the complete range of frictional behaviors for the Drucker-Prager solid and by lifting the restriction on the incompressibility of the solid for the estimation of morphology factors that describe the mechanical interaction between material phases. The LCC strength homogenization is implemented in a multiscale thought model applicable to geomaterials, which serves as a generalized framework for quantitative assessment of effects of material composition, grain-scale properties, microstructure, and interface conditions on the overall strength of the porous composite.