Biomechanical study of the constitutive laws of vascular walls

Abstract

Static mechanical behaviors of three different arterial walls were examined through changes in external radius due to distending pressure. In order to examine the distensibility of these vessels, distension ratio was defined as the ratio of eternal radius at each pressure to that at zero pressure. Linear relations were observed between the logarithmic pressure and the distension ration, and they were described by on exponential function. Two parameters used in this equation were related quantitatively to the area fraction of elastin or collagen component occupied in the cross section of wall. Stress-strain relation was then determined from their pressure-diameter data by using finite-deformation theory. An exponential function was established between tangential stress and tangenital strain. These results can be used to study the resistance of arterial walls to cardio-vascular disease.