Multiscale, structure-based modeling for the elastic mechanical behavior of arterial walls

Area of Science:

• Biomedical Engineering
• Materials Science
• Computational Mechanics

Background:

• Arterial wall mechanics are complex and difficult to model accurately.
• Existing models often overlook the intricate 3D collagen network structure's role.
• Understanding this structure-property relationship is crucial for cardiovascular research.

Purpose of the Study:

• To develop a multiscale, structural model of the arterial wall.
• To investigate how the collagen network architecture influences mechanical properties.
• To elucidate the role of the noncollagenous matrix in arterial mechanics.

Main Methods:

• A novel model incorporating a collagen fiber network and a neo-Hookean noncollagenous matrix.
• Application of volume-averaging theory to the collagen network.
• Utilizing structural parameters of the collagen microstructure instead of macroscopic laws.

Main Results:

• The model accurately predicted experimental data for decellularized porcine carotid arteries.
• Predicted increased circumferential compliance with axial stretch.
• Showed the noncollagenous matrix remains in compression even at large extensions, preventing network collapse.

Conclusions:

• The developed model accurately captures arterial wall passive elastic behavior.
• Collagen fiber-fiber interactions are key to modeling artery mechanics with few parameters.
• The noncollagenous matrix supports the collagen network, rather than directly resisting load, even at small strains.