3D porous particles: shape and contact modelling for DEM simulations: updates and challenges

The growing demand for energy-efficient and sustainable construction materials has driven interest in lightweight particulate composites (LPCs) incorporating fly ash cenospheres (FACs) within calcium aluminate cement (CAC) matrices. FACs improve mechanical strength, thermal insulation, and environmental sustainability due to their high specific strength, partial pozzolanic activity, and hollow morphology. To accurately predict the thermomechanical behavior of these heterogeneous composites, a multiscale modeling framework combining finite element method (FEM) homogenization and emerging discrete element method (DEM) strategies is employed. FEM-based homogenization demonstrates high accuracy and computational efficiency in estimating effective properties, while DEM models tailored for hollow particles are under development to capture packing behavior and contact mechanics more realistically. Micro-computed tomography enables precise reconstruction of cenosphere-filled microstructures for FEM simulations, revealing the critical role of wall thickness and particle distribution in composite performance. This study lays the groundwork for a novel DEM framework and thermomechanical contact protocols specifically designed for hollow particles, advancing the predictive modeling of sustainable lightweight composites.