Pressurization Of Axially Prestretched Tube: Consequences For Arterial Mechanics

It is well known that in their in situ position, arteries are axially prestretched. They retract upon excision as a consequence. Studies of the prestretch have shown that it depends on location in arterial tree. Axial prestretch increases with increasing distance from the heart. It has also been shown that the prestretch changes with age. Aging damages internal architecture of arteries and consequently longitudinal pretension is gradually loosen. Results obtained in laboratory experiments document that there is specific value of the prestretch under which axial deformation of the pressurized artery is negligible. Under such conditions, mechanical work performed by the pressure on axial displacements is negligible which is advantageous from biomechanical point of view. In the present study, by adopting the Gent model of the strain energy density function to characterize mechanical properties of the artery and assuming that this artery satisfies assumptions of the membrane theory, it will be shown that the value of prestretch, which minimizes axial displacement, also maximizes internal volume attained in the pressurization of the tube.