Influence of microstructure on the mechanical behavior of open-porous materials under large strains

Open-porous materials are characterized by a complex morphology consisting of an interconnected solid network and voids. The mechanical performance of these materials is strongly governed by their underlying microstructure. This study presents a computational framework to investigate the structure–property relationships in open-porous materials by explicitly modeling the effects of pore-size distribution (PSD), solid fraction, and pore wall geometry. Microstructures with tunable PSDs are generated using Laguerre-Voronoi tessellation based on random closed packing of polydisperse spheres, allowing precise control over pore morphology. A finite element framework with the elastoplastic material model is used to study the macroscopic behavior under compressive loading. The model response is validated against experimental data from aerogel and foam materials. The study reveals that while the solid fraction alone governs the bulk elastic modulus and plastic collapse stress through well-established scaling laws, the PSD critically affects the post-yield behavior, including the plateau and densification regimes under large strains. This study highlights the importance of PSD beyond classical density-based models and provides a predictive design strategy to tailor open-porous materials to application-specific mechanical requirements.