Effect of Normal Stress on the Torsional Shear Response of the Porcine Descending Aorta

Studying the mechanical properties of aortic tissue is important in determining future medical action regarding both healthy and diseased conditions. Although uniaxial and bi-axial experimental testing has been previously conducted on porcine aortas, shear testing is still being preliminarily explored. We studied the response of porcine descending thoracic aorta under cyclic torsional shear at five different compressive strains (5%, 10%, 15%, 20%, and 25%). From preliminary experimental results, we found that varying the normal compressive strain has a significant effect on the shear response. It can be concluded that porcine aorta should be treated as a viscoelastic material.