Layered double hydroxides reinforced epoxy composites: Computational analysis of microstructure effect on strength

• The addition of LDH to epoxy enhances stiffness but increases brittleness. • Damage mechanisms such as crack pinning and crack deflection were observed. • Epoxy/LDH composites are feasible for corrosion-protective coatings. This paper analyses the mechanical and damage behaviour of epoxy composites incorporating magnesium–aluminium layered double hydroxides (LDH), which have potential applications as corrosion protective coatings. The analysis of these composites was carried out by developing a computational model based on numerical homogenisation approach, employing the micromechanical finite element method. The influence of the elastic modulus, aspect ratio and weight fractions of the LDH particles on the mechanical and damage behaviour of epoxy/LDH composites was investigated. Damage modelling was performed, capturing both crack formation and evolution. Damage mechanisms such as crack pinning and crack deflection due to the LDH particles were observed. The modelling demonstrated that with an increase in the weight fraction of LDH, the composite became stiffer and more brittle. Adding up to 5 wt% LDH particles to epoxy increased the elastic modulus of the composite by nearly 20%. The strain at break was reduced to 2 %. The model was validated against experimental data, demonstrating its ability to predict the behaviour of epoxy/LDH composites. The findings indicate that epoxy/LDH composites exhibit enhanced stiffness, making them suitable for practical applications as corrosion-protective coatings.