Predicting mode I interlaminar fracture toughness of seawater-aged CFRP laminates: a phenomenological model with Monte Carlo simulation

The Mode I interlaminar fracture toughness ( G Ic ) of seawater-aged carbon fiber reinforced polymer (CFRP) composites depends on a delicate balance between opposing hygrothermal aging mechanisms, further influenced by salt-induced effects. This complexity creates a gap in predictive models for post-aging interlaminar properties, hindering the marine application of CFRP composites. To address this challenge, we propose a phenomenological model for quantitatively predicting the G Ic of CFRP subjected to seawater aging at different concentrations, based on seawater aging and delamination failure mechanisms. Our model predicts G Ic directly from fundamental material properties, such as equilibrium moisture content and glass transition temperature, and estimates G Ic scatter bands under different seawater concentrations using Monte Carlo simulations. Validation with computational and experimental data reveals a maximum mean absolute percentage error (MAPE) of 7.59% and an average MAPE of 4.71%. This model addresses the gap in quantitative prediction methods for G Ic after seawater aging, providing enhanced mechanistic perspectives and demonstrating clear engineering applicability.