Anisotropic residual stresses in arteries

Area of Science:

• Biomechanics
• Biomaterials Science
• Computational Biology

Background:

• Arterial walls exhibit complex mechanical behaviors due to distinct microstructures in their layers (intima, media, adventitia).
• Residual stresses significantly influence arterial function and disease progression.
• Previous models often oversimplify the anisotropic nature of arterial tissues.

Purpose of the Study:

• To investigate the impact of anisotropy on residual stress analysis in human abdominal aortas.
• To develop a more accurate model for residual deformations in individual arterial layers.
• To evaluate the limitations of conventional methods in capturing complex arterial mechanics.

Main Methods:

• Utilized the Holzapfel and Ogden model for residual deformations, incorporating experimental data from human abdominal aortas.
• Employed the most general form of strain-energy function to derive layer-specific residual stresses.
• Integrated systematic experimental data on mechanical and structural properties of aortic layers.

Main Results:

• Anisotropy plays a crucial role in accurately modeling residual stresses in arteries.
• Significant variability in residual stresses exists even within the same tissue type (abdominal aorta).
• The conventional opening angle method has limitations in accounting for complex, anisotropic residual deformations.

Conclusions:

• Accurate modeling of arterial residual stresses requires accounting for material anisotropy and layer-specific properties.
• Findings highlight the need for advanced constitutive models that capture the nonlinear and anisotropic behavior of arterial tissues.
• Understanding residual stresses is vital for predicting arterial response under physiological loading conditions.