Abstract
The ascending thoracic aorta is poorly understood mechanically, especially its risk of dissection. To make better predictions of dissection risk, more information about the multidimensional failure behavior of the tissue is needed, and this information must be incorporated into an appropriate theoretical/computational model. Toward the creation of such a model, uniaxial, equibiaxial, peel, and shear lap tests were performed on healthy porcine ascending aorta samples. Uniaxial and equibiaxial tests showed anisotropy with greater stiffness and strength in the circumferential direction. Shear lap tests showed catastrophic failure at shear stresses (150-200 kPa) much lower than uniaxial tests (750-2500 kPa), consistent with the low peel tension (60 mN/mm). A novel multiscale computational model, including both prefailure and failure mechanics of the aorta, was developed. The microstructural part of the model included contributions from a collagenreinforced elastin sheet and interlamellar connections representing fibrillin and smooth muscle. Components were represented as nonlinear fibers that failed at a critical stretch. Multiscale simulations of the different experiments were performed, and the model, appropriately specified, agreed well with all experimental data, representing a uniquely complete structure-based description of aorta mechanics. In addition, our experiments and model demonstrate the very low strength of the aorta in radial shear, suggesting an important possible mechanism for aortic dissection.
| Original language | English (US) |
|---|---|
| Article number | 031005 |
| Journal | Journal of Biomechanical Engineering |
| Volume | 139 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1 2017 |
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Keywords
- Biomechanics
- Failure
- Peel
- Shear
Cite this
Failure of the porcine ascending aorta : Multidirectional experiments and a unifying microstructural model. / Witzenburg, Colleen M.; Dhume, Rohit Y.; Shah, Sachin B.; Korenczuk, Christopher E.; Wagner, Hallie P.; Alford, Patrick W; Barocas, Victor H.
In: Journal of Biomechanical Engineering, Vol. 139, No. 3, 031005, 01.03.2017.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Failure of the porcine ascending aorta
T2 - Multidirectional experiments and a unifying microstructural model
AU - Witzenburg, Colleen M.
AU - Dhume, Rohit Y.
AU - Shah, Sachin B.
AU - Korenczuk, Christopher E.
AU - Wagner, Hallie P.
AU - Alford, Patrick W
AU - Barocas, Victor H
PY - 2017/3/1
Y1 - 2017/3/1
N2 - The ascending thoracic aorta is poorly understood mechanically, especially its risk of dissection. To make better predictions of dissection risk, more information about the multidimensional failure behavior of the tissue is needed, and this information must be incorporated into an appropriate theoretical/computational model. Toward the creation of such a model, uniaxial, equibiaxial, peel, and shear lap tests were performed on healthy porcine ascending aorta samples. Uniaxial and equibiaxial tests showed anisotropy with greater stiffness and strength in the circumferential direction. Shear lap tests showed catastrophic failure at shear stresses (150-200 kPa) much lower than uniaxial tests (750-2500 kPa), consistent with the low peel tension (60 mN/mm). A novel multiscale computational model, including both prefailure and failure mechanics of the aorta, was developed. The microstructural part of the model included contributions from a collagenreinforced elastin sheet and interlamellar connections representing fibrillin and smooth muscle. Components were represented as nonlinear fibers that failed at a critical stretch. Multiscale simulations of the different experiments were performed, and the model, appropriately specified, agreed well with all experimental data, representing a uniquely complete structure-based description of aorta mechanics. In addition, our experiments and model demonstrate the very low strength of the aorta in radial shear, suggesting an important possible mechanism for aortic dissection.
AB - The ascending thoracic aorta is poorly understood mechanically, especially its risk of dissection. To make better predictions of dissection risk, more information about the multidimensional failure behavior of the tissue is needed, and this information must be incorporated into an appropriate theoretical/computational model. Toward the creation of such a model, uniaxial, equibiaxial, peel, and shear lap tests were performed on healthy porcine ascending aorta samples. Uniaxial and equibiaxial tests showed anisotropy with greater stiffness and strength in the circumferential direction. Shear lap tests showed catastrophic failure at shear stresses (150-200 kPa) much lower than uniaxial tests (750-2500 kPa), consistent with the low peel tension (60 mN/mm). A novel multiscale computational model, including both prefailure and failure mechanics of the aorta, was developed. The microstructural part of the model included contributions from a collagenreinforced elastin sheet and interlamellar connections representing fibrillin and smooth muscle. Components were represented as nonlinear fibers that failed at a critical stretch. Multiscale simulations of the different experiments were performed, and the model, appropriately specified, agreed well with all experimental data, representing a uniquely complete structure-based description of aorta mechanics. In addition, our experiments and model demonstrate the very low strength of the aorta in radial shear, suggesting an important possible mechanism for aortic dissection.
KW - Biomechanics
KW - Failure
KW - Peel
KW - Shear
UR - http://www.scopus.com/inward/record.url?scp=85010285159&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85010285159&partnerID=8YFLogxK
U2 - 10.1115/1.4035264
DO - 10.1115/1.4035264
M3 - Article
VL - 139
JO - Journal of Biomechanical Engineering
JF - Journal of Biomechanical Engineering
SN - 0148-0731
IS - 3
M1 - 031005
ER -