Finite element analysis of the water diffusion behaviour in pigmented epoxy coatings under alternating hydrostatic pressure

The water diffusion behaviour in pigmented epoxy coatings under alternating hydrostatic pressure (AHP) has been calculated by the finite element method. The water diffusion in the coating under AHP follows the non-Fickian diffusion, which is caused by cracks and superposed by the occurrences of many independent Fickian diffusion processes. The cracks largely contribute to the water absorption of the coating. If the occurrence time of the cracks is measured by the experiment, the lifetime of the coating under AHP can be quickly determined.