Computational Modeling of the Mechanical Behavior of 3D Hybrid Organic–Inorganic Nanocomposites

In this study, a computational model of a three-dimensional (3D) hybrid nanocomposite was analyzed using the cohesive finite element method. This model contains hard mineral nanograins bonded by a relatively soft and thin organic adhesive layer to mimic the ultrastructure of biological ceramics such as bone and nacre. The simulation results showed that the adhesive phase, which comprises only a few percent of the nanocomposite volume, significantly enhanced the toughness through widespread cohesive damage, diffuse nanocrack formation, and complex trajectories of crack growth. In addition, the 3D model revealed the strain-hardening/-softening behavior of the nanocomposite, which was not captured by two-dimensional models, highlighting the importance of 3D architecture in the mechanical behavior of the natural materials. The mechanical properties of the nanocomposite were comparable to those of bone and nacre, indicating that a damage-tolerant behavior of the natural materials can be attained by using only small amount of a tough adhesive within the 3D microstructure of brittle minerals.