Swelling of an internally pressurized nonlinearly elastic tube with fiber reinforcing

We study the effect of swelling on the mechanical response of fiber reinforced tubes within the context of finite elastic deformation. The fibers themselves do not swell, setting up a competition between the matrix, for which swelling tends to open the tube, and the fibers, for which swelling tends to constrict the tube. Balancing these tendencies in the constitutive response can lead to an internal channel opening that remains relatively constant over a wide range of swelling. Further, the hoop stress on the inner wall in such a situation may be compressive, rather than tensile. Both effects may be advantageous in certain settings, including biological organ systems.