Characterization of mechanical damage and viscoelasticity on aortas from guinea pigs subjected to hypoxia

This study investigated the passive mechanical behavior of guinea pig aortas under chronic hypobaric hypoxia using combined uniaxial and biaxial mechanical testing coupled with constitutive modeling. Researchers developed and calibrated an anisotropic visco-hyperelastic model incorporating asymmetric collagen fiber dispersion, anisotropic damage, and orthotropic viscoelasticity. Experimental results from hypoxic and normoxic groups revealed no significant differences in elastic modulus, stress–strain behavior, or energy dissipation, suggesting that long-term hypoxia does not alter the intrinsic passive mechanical response of the aortic wall. Finite element simulations of bulge pressurization tests confirmed the predictive performance of the constitutive model, supporting its application to cardiovascular damage modeling.