Hygrothermal ageing modeling and numerical testing of unidirectional polymeric composites

Moisture severely affects aerospace structures and offshore platforms during their service life span. It deteriorates the mechanical performance of polymeric composites through long term and cyclic hygrothermal ageing. This reduction in mechanical performance must be considered during product design to ensure long-term structure endurance. In order to decide the long-term moisture effects on composite components, they are exposed to a rapid moisture conditioning. Presently the available qualified methodologies allowing only simple geometry and an assumption that diffusivity rates are independent of the flow path or direction. Therefore a more advanced finite element method is required. In this research work the finite-element analysis was performed to study the moisture diffusion in unidirectional composites. The final goal for this study was to determine the exposure time for rapid moisture conditioning that produces the most accurate moisture distribution in composite laminates.