Mechanics of nonlinearly elastic tubes: Effect of axial prestretching and consequences for the biomechanics of human arteries

Abstract: Axial prestretching can significantly affect the mechanical response of an inflated tube. This phenomenon is known, for example in the biomechanics of the cardiovascular system, where arteries, if excised from a body, manifest non-negligible shortening. It is clear that longitudinal prestretching leads to a reduction in the axial deformation that accompanies the pressure pulse transmitted through a tube made of a material exhibiting large-strain stiffening. Somewhat surprisingly, however, longitudinal prestressing increases the arterial distensibility and thus contributes to a higher relative volume that can be transmitted during the pressure pulse. It even appears that some material models, such as the Gent strain energy density function, have an axial strain inversion point at which the axial strain remains constant during pressurization while the relative volume is at its maximum. However, due to age-related changes, the value of the arterial axial prestretch decreases significantly with age. Simulations considering nonlinear anisotropic material for the arterial wall show that even though this value decreases, it still has a beneficial effect on the value of circumferential distensibility. Similarly, during the transition from elastic to viscoelastic behavior, we observe that, from the perspective of the thin-walled tube inflation problem, the longitudinal prestretch is advantageous for the attainable volume.

MathematicsPhysics

Audience: researchers in the topic

Nečas Seminar on Continuum Mechanics

Series comments: This seminar was founded on December 14, 1966.

Faculty of Mathematics and Physics, Charles University, Sokolovská 83, Prague 8. If not written otherwise, we will meet on Mondays at 15:40 in lecture hall K3 (2nd floor)