Micromechanical model for cohesive materials based upon pseudo-granular structure

摘要

A micromechanical model for cohesive materials is derived by considering their underlying microstructure conceptualized as a collection of grains interacting through pseudo-bonds. The pseudo-bond or the inter-granular force-displacement relations are formulated taking inspiration from the atomistic-level particle interactions. These force-displacement relationships are then used to derive the incremental stiffnesses at the grain-scale, and consequently, obtain the sample-scale stress-strain relationship of a representative volume of the material. The derived relationship is utilized to study the stress-strain and failure behavior including the volume change and "brittle" to "ductile" transition behavior of cohesive materials under multi-axial loading condition. The model calculations are compared with available measured data for model validation. Model predictions exhibit both quantitative and qualitative consistency with the observed behavior of cohesive material.