Modelling the mechanical response of elastin for arterial tissue

Area of Science:

• Biomechanics
• Materials Science
• Biomedical Engineering

Background:

• Arterial tissue mechanics are crucial for understanding cardiovascular health.
• Elastin is a key component of arteries, providing elasticity.
• Accurate constitutive models are needed to simulate arterial behavior.

Purpose of the Study:

• To compare two constitutive models for arterial elastin: neo-Hookean and a modified model (n=32).
• To analyze model performance under uniaxial extension and cylindrical membrane inflation.
• To evaluate model predictions against experimental data for elastin.

Main Methods:

• Analysis of neo-Hookean (Psi=c(I(1)-3)) and Zulliger et al. (Psi=c(I(1)-3)(3/2)) models.
• Simulations for uniaxial extension of an elastinous sheet.
• Simulations for inflation of a cylindrical elastinous membrane.
• Comparison of model outputs (stress-strain, tangent modulus, pressure-stretch) with experimental elastin data.

Main Results:

• The neo-Hookean model accurately predicts single elastin fiber response but fails for arterial elastin (toe region, modulus increase).
• The n=32 model shows nonlinear behavior deviating from experimental data.
• Significant qualitative differences observed in pressure-stretch relationships between models.

Conclusions:

• The neo-Hookean model, despite limitations, appears more accurate for elastin mechanical response than the n=32 model.
• Neither model fully captures the complex mechanical behavior of arterial elastin.
• Further refinement of constitutive models for arterial elastin is warranted.