Influence of Artery Unfoldment on Its Mechanical Response

Abstract

This study investigates the influence of artery unfoldment on its mechanical response in planar tension test. Inflation test was chosen for comparison because, with the axial stretch λz = 1, it also keeps plane strain condition. Both tests were simulated in silico using finite element method. The geometry models correspond to aorta and common carotid artery with distinguished two layers within the arterial wall; a homogenous wall model was also used for comparison. Material models were acquired by fitting the uniaxial tension tests of human carotid arteries dissected into media and adventitia layers with 3 rd order Yeoh hyperelastic model. The results showed that the artery segment straightening leads to a non-uniform stress distribution throughout the specimen thickness with the maximum stress located at the inner surface of the artery. By comparing stresses (averaged throughout the thickness) at specified strain levels up to 30 %, the influence of specimen unfoldment was estimated with inflation test taken as a basis. For the carotid artery, stresses in the planar tension test were higher by 27−61 % while for the aorta the difference was between 8 and 17 %. The difference between individual arteries occurs due to the varying thickness-to-radius ratio.