Measurement of Poisson´s ratio of bovine aorta using Digital Image Correlation

Digital image correlation (DIC) was adopted to examine the mechanical behavior of arterial tissue from the bovine aorta. Rectangular sections comprised of the intimal and medial layers were excised from the descending aorta and loaded in displacement control uniaxial tension up to 40% elongation. Specimens of silicon rubber sheet were also prepared and served as a benchmark material in the application of DIC for the evaluation of large strains; the elastomer was loaded to 50% elongation. The arterial specimens exhibited a non-linear hyperelastic stress-strain response and the stiffness increased with percent elongation. Poisson´s ratio is observed to increase when specimens are subjected to uniaxial stress in the axial direction, while Poission´s ratio is observed to decrease when specimens are subjected to uniaxial stress in the circumferential direction.