Diffusion coefficient is an important parameter used for theoretical estimation of moisture content in a body when it is exposed to a moist environment. The diffusion coefficient of FRP materials usually depends on several parameters, such as the diffusivities of constituents, fiber volume fraction, moisture concentration of the environment, and temperature. The shapes of reinforcing fibers also have definite effects on the diffusion coefficient. The present problem is aimed at studying the effects of the shapes of impermeable reinforcing fibers on diffusivity. A single fiber reinforced composite model is chosen for the present study. The shapes of the fibers are either circular or elliptical, but they have the same cross-sectional area. It is observed that the diffusivity shows a marked dependence on the shapes of the fiber, even though the volume fraction of the fiber and other parameters are kept constant.
