Diffusion Behavior in Sandwich Composites: Modeling and Experiment

Abstract

This study examines the moisture sorption behaviors in neat epoxy, glass fiberreinforced/ epoxy composites, and polyurethane foam core immersed in deionized water at 50 °C. In addition, the moisture diffusion in sandwich composites comprising of the above constituents is also studied. Diffusivity coefficients are first calibrated from experimental data. The classical Fickian diffusion model was applied to simulate the moisture sorption of liquid in the polymer composites. For fiber-reinforced polymer composites, the Springer diffusion model was considered. A finite difference method is used to solve for the classical Fickian diffusion model and the Springer diffusion model. The Fickian model is used to predict the one-dimensional moisture diffusion in thin plates and the multi-axial three-dimensional moisture diffusion in foams. With the calibrated diffusivities for the above constituents, the diffusion behavior in sandwich composite is predicted.