Moisture diffusion in variously shaped fibre reinforced composites

The versatility of composite material lies in its unique characteristics of high strength and stiffness combined with light weight. Like all other materials this is also susceptible to moisture coupled with temperature. Moisture susceptibility is directly associated with the diffusion of moisture through polymeric composites. Moisture diffusion coefficients of polymer composites are found to depend on a number of factors, such as moisture concentration and environmental temperature, fibre volume fraction, and the diffusivity of the fibre (if permeable) and polymer matrix. Moisture diffusion coefficients of polymer composites also depend on the shape of the reinforcing fibre. In the present investigation single fibre composite models reinforced with variously shaped reinforcing fibres are used for the evaluation of the diffusion coefficients. The finite element analysis approach is developed based on the Galerkin formulation using nine-node isoparametric elements.