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

Figures

• 

  Fig. 1. (a) Schematic longitudinal (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textrm{z}$$\end{document}) and circumferential (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\theta }$$\end{document}) specimen configurations. (b) Initial dimensions of specimens for biaxial testing. (c) Initial dimensions of specimens for uniaxial testing. (d) Initial thickness of specimens

• 

  Fig. 2. Calibration procedure for the constitutive model. Description of the four stages (I to IV), detailing the optimization method and initial, calibrated (free), and fixed sets of constitutive model parameters at each step

• 

  Fig. 3. Bulge test simulation. (a) Undeformed configuration and mean fiber directions. (b) Finite element mesh. (c) Typical deformed configuration and analysis point ‘A’. (d) Bulge test experimental setup

• 

  Fig. 4. Cauchy stress (in kPa) versus stretch, uniaxial relaxation (a, b) and biaxial (c, d) tensile tests, normoxic group (Nx). Longitudinal (z) and circumferential (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}) directions

• 

  Fig. 5. Cauchy stress (in kPa) versus stretch, uniaxial relaxation (a, b) and biaxial (c, d) tensile tests, hypoxic group (Hx). Longitudinal (z) and circumferential (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}) directions

• 

  Fig. 6. Constitutive model calibration for a typical animal (Nx-01) of the normoxic group (Nx): Cauchy stress (in kPa) versus stretch of uniaxial relaxation (a,b) and biaxial (c) tensile tests; (d) damage – on matrix (‘m’) or fibers (‘f’) – versus stretch of uniaxial relaxation (Uniax.) and biaxial (Biax.) tensile tests. Longitudinal (z) and circumferential (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}) directions.

• 

  Fig. 7. Constitutive model calibration for a typical animal (Hx-02) of the hypoxic group (Hx): Cauchy stress (in kPa) versus stretch of uniaxial relaxation (a,b) and biaxial (c) tensile tests; (d) damage – on matrix (‘m’) or fibers (‘f’) – versus stretch of uniaxial relaxation (Uniax.) and biaxial (Biax.) tensile tests. Longitudinal (z) and circumferential (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}) directions.

• 

  Fig. 8. Sensitivity analysis of the constitutive model calibration (5% perturbation) for a typical animal (Nx-01) of the normoxic group (Nx): Mean, 95% confidence interval, and experimental Cauchy stress (in kPa) versus stretch of uniaxial relaxation (a) and biaxial (b) tensile tests; (c-r) First-order sensitivity index of constitutive model parameters. Longitudinal (z) and circumferential (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}) directions.

• 

  Fig. 9. Sensitivity analysis of the constitutive model calibration (5% perturbation) for a typical animal (Hx-02) of the hypoxic group (Hx): Mean, 95% confidence interval, and experimental Cauchy stress (in kPa) versus stretch of uniaxial relaxation (a) and biaxial (b) tensile tests; (c-r) First-order sensitivity index of constitutive model parameters. Longitudinal (z) and circumferential (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}) directions.

• 

  Fig. 10. Bulge test simulation results at point ‘A’, normoxic group (Nx). Pressure (in kPa) versus: (a) vertical displacement (in mm); (b) maximum Cauchy normal stress (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textrm{max}\{\sigma _{11},\sigma _{22}\}$$\end{document}, in kPa); (c) damage to fibers (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$D_{\textrm{f}}$$\end{document}); (d) energy release rate in fibers (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$S_{\textrm{f}}$$\end{document}, in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy}…

• 

  Fig. 11. Bulge test simulation results at point ‘A’, hypoxic group (Hx). Pressure (in kPa) versus: (a) vertical displacement (in mm); (b) maximum Cauchy normal stress (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textrm{max}\{\sigma _{11},\sigma _{22}\}$$\end{document}, in kPa); (c) damage to fibers (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$D_{\textrm{f}}$$\end{document}); (d) energy release rate in fibers (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$S_{\textrm{f}}$$\end{document}, in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs}…