The Effect of Collagen Fiber Directional Distribution on the Mechanical Response of the Vascular Wall

Constitutive equations reflecting well the microstructure are fundamental for the detailed stress analysis of the arterial tissue. Vascular tissue is an inhomogeneous and incompressible material which undergoes large deformations and shows highly anisotropic nonlinear behavior. These properties make strain energy functions (SEFs) a suitable tool to derive constitutive equations. Structural constitutive models try to integrate the histological and morphological characteristics of the tissue by introducing parameters with physical meaning, such as the fraction of each wall constituent, the elastic properties of single elastin or collagen fibers or the angle of collagen fibers.