Material Properties of Aorta From Nanoindentaion Tests

Aorta is assumed as a homogenous material in current finite element models, but in fact aorta is composed of three major layers: intima, media, and adventitia with different microstructural organizations that result in different material properties. Understanding the material properties of these layers is essential for studying the local mechanisms of deformation, force transmission, and failure in aorta. The material properties of aorta wall layers were determined from nano-indentation tests. The results show that the value of shear modulus generally increases from the inner wall toward the outer wall. Aorta material time dependency was independent from the radial orientation. This study explains why aorta rupture initiates near the inner wall and propagates toward the outer wall.