An Integrated Approach to Analyze Long-term Moisture Transport inHoneycomb-core Sandwich Panels

A predictive model for the time evolution of moisture uptake within a honeycomb-core sandwich has been developed. The model takes into account the water diffusion into the skins as well as into the honeycomb part of the sandwich. Experimental evidence has been found of hydrolysis of the aramidic pulp of the honeycomb, which has been consequently accounted for in the model through an irreversible reaction term. The relevant parameters of the model (diffusivities, solubilities, and aramidic hydrolysis kinetic constants), for each single component making up the sandwich, have been experimentally evaluated at several temperatures and relative humidities. Predictions of the model successfully compare with experimentally determined water uptake kinetics into the whole sandwich.