Validation of a thermal runaway criterion for thick polymer composites

This work presents the first comprehensive validation and optimization of an analytical model for predicting thermal runaway and peak exothermal overshoot during curing of thick polymer composite laminates. Unlike previous studies, a novel second derivative criterion is introduced to objectively identify thermal runaway in numerical simulations, enabling direct comparison with analytical predictions. The model was evaluated across a wide range of Arrhenius numbers and dimensionless mold temperatures representative of real processing conditions, enabling optimization of model constants using a least squares fitting procedure. The findings confirm that the analytical model, when enhanced with fitted parameters, predicts critical conditions with less than 10% error across most of the investigated parameter space, offering a fast and reliable tool for estimating safe processing limits in thick composite laminates.