In this manuscript, we present a combined experimental and computational technique that can identify the heterogeneous elastic properties of planar soft tissues. By combining inverse membrane analysis, digital image correlation, and bulge inflation tests, we are able to identify a tissue’s mechanical properties locally. To show how the proposed method could be implemented, we quantified the heterogeneous material properties of a human ascending thoracic aortic aneurysm (ATAA). The ATAA was inflated at a constant rate using a bulge inflation device until it ruptured. Every 3 kPa images were taken using a stereo digital image correlation system. From the images, the three-dimensional displacement of the sample surface was determined. A deforming NURBS mesh was derived from the displacement data, and the local strains were computed. The wall stresses at each pressure increment were determined using inverse membrane analysis. The local material properties of the ATAA were then identified using the pointwise stress and strain data. To show that it is necessary to consider the heterogeneous distribution of the mechanical properties in the ATAA, three different forward finite element simulations using pointwise, elementwise, and homogeneous material properties were compared. The forward finite element predictions revealed that heterogeneous nature of the ATAA must be accounted for to accurately reproduce the stress–strain response.
Bulge inflation test Heterogeneous material properties Digital image correlation Inverse elastostatic analysis Thoracic aneurysm
This is a preview of subscription content, log in to check access.
This work was supported in part by the University of Iowa Mathematical and Physical Sciences Funding Program. Dr. Davis was supported by the Whitaker International Scholars Program. The authors thank Dr. Aaron Romo for his assistance with the experimental protocol.
Belytschko T, Liu WK, Organ D, Fleming M, Krysl P (1996) Meshless methods: an overview and recent developments. Comput Methods Appl Mech Eng 139:3–47zbMATHCrossRefGoogle Scholar
Choudhury N, Bouchot O, Rouleau L, Tremblay D, Cartier R, Butany J, Mongrain R, Leask RL (2009) Local mechanical and structural properties of healthy and diseased human ascending aorta tissue. Cardiovasc Pathol 18(2):83–91. doi:10.1016/j.carpath.2008.01.001CrossRefGoogle Scholar
Coudrillier B, Tian J, Alexander S, Myers KM, Quigley HA, Nguyen TD (2012) Biomechanics of the human posterior sclera: age and glaucoma related changes measured using inflation testing. Investig Ophthalmol Vis Sci 53(4):1714–1728. doi:10.1167/iovs.11-8009CrossRefGoogle Scholar
Haskett D, Johnson G, Zhou A, Utzinger U (2010) Microstructural and biomechanical alterations of the human aorta as a function of age and location. Biomech Model Mechanobiol 9(6):725–736. doi:10.1007/s10237-010-0209-7CrossRefGoogle Scholar
Hughes TJR, Cottrell JA, Bazilevs Y (2005) Isogeometric analysis: CAD, finite elements, NURBS, exact geometry and mesh refinement. Comput Methods Appl Mech Eng 194(39):4135–4195zbMATHMathSciNetCrossRefGoogle Scholar
Miller K, Lu J (2013) On the prospect of patient-specific biomechanics without patient-specific properties of tissues. J Mech Behav Biomed Mater 27:154–166CrossRefGoogle Scholar
Mohan DH, Melvin JW (1983) Failure properties of passive human aortic tissue. II—biaxial tension tests. J Biomech 16(1):31–44CrossRefGoogle Scholar
Myers KM, Coudrillier B, Boyce BL, Nguyen TD (2010) The inflation response of the posterior bovine sclera. Acta Biomater 6(11):4327–4335. doi:10.1016/j.actbio.2010.06.007
Ní Annaidh A, Bruyère K, Destrade M, Gilchrist MD, Otténio M (2012) Characterization of the anisotropic mechanical properties of excised human skin. J Mech Behav Biomed Mater 5(1):139–148. doi:10.1016/j.jmbbm.2011.08.016
Okamoto RJ, Wagenseil JE, DeLong WR, Peterson SJ, Kouchoukos NT, Sundt TM III (2002) Mechanical properties of dilated human ascending aorta. Ann Biomedial Eng 30:624–635. doi:10.1114/1.1484220CrossRefGoogle Scholar
Pham T, Martin C, Elefteriades JA, Sun W (2013) Biomechanical characterization of ascending aortic aneurysm with concomitant bicuspid aortic valve and bovine aortic arch. Acta Biomater 9:7927–7936. doi:10.1016/j.actbio.2013.04.021CrossRefGoogle Scholar
Vorp DA, Shiro BJ, Ehrlich MP, Juvonen TS, Ergin MA, Griffith BP (2003) Effect of aneurysm on the tensile strength and biomechanical behavior of the ascending thoracic aorta. Ann Thorac Surg 75:1210–1214CrossRefGoogle Scholar
Wilson JS, Baek S, Humphrey JD (2012) Importance of initial aortic properties on the evolving regional anisotropy, stiffness and wall thickness of human abdominal aortic aneurysms. J R Soc Interfac 9:2047–2058. doi:10.1098/rsif.2012.0097CrossRefGoogle Scholar
Zhao X, Chen X, Lu J (2009) Pointwise identification of elastic properties in nonlinear hyperelastic membranes—part II: experimental validation. J Appl Mech 76(6):061014. doi:10.1115/1.3130810CrossRefGoogle Scholar
Zhao X, Raghavan ML, Lu J (2011) Characterizing heterogeneous properties of cerebral aneurysms with unknown stress-free geometry: a precursor to in vivo identification. J Biomech Eng T ASME 133(2):051008CrossRefGoogle Scholar
Zhao X, Raghavan ML, Lu J (2011) Identifying heterogeneous anisotropic properties in cerebral aneurysms: a pointwise approach. Biomech Model Mechanobiol 10(2):177–189CrossRefGoogle Scholar