Experimental characterization of rupture in human aortic aneurysms using a full-field measurement technique

Abstract

The present study aims at investigating biomechanical failure behaviour of human aneurismal aortic tissues so as to diagnose the rupture risk of aneurysms more accurately. An inflation test is performed on aneurismal aortic tissues up to failure and full-field measurements are achieved using stereo digital image correlation. Then, an appropriate constitutive model derived from histological structure of arteries is adopted to retrieve the Cauchy stress. The virtual fields method is used as an inverse procedure to identify material parameters. Next, the Cauchy stress components are calculated from the identified parameters and the measured Lagrange strain fields. Finally, an important stress parameter which can quantify the strength of aneurismal tissues is derived from the failure stress of aneurismal tissues.

Elastic stiffness characterization using three-dimensional full-field deformation obtained with optical coherence tomography and digital volume correlation

“…So far, the VFM has successfully been applied to the identification of constitutive parameters for linear elastic materials such as composites, [30][31][32][33] elasto-plasticity for metals [34][35][36] as well as hyperelasticity for soft and biological materials such as artery walls. 37,38 The aim of this study is to develop an effective methodology to investigate the internal deformation behavior of silicone rubber phantoms under load and to identify their elastic stiffness parameters. This methodology will eventually be applied to study the mechanical properties of biological tissues, such as the vertebrate eye cornea.…”

Nondestructive mechanical characterization of developing biological tissues using inflation testing

“…This reduction was most evident in the fiberreinforced materials, where more parameters were to be estimated. Without such an initial estimate, an inverse FE analysis with 3D elements is computationally costly, therefore previous studies typically resorted to faster methods such as shell meshes [18,21,22,23,39,36] or analytical solutions as used in the initial estimate [20,37]. These methods can provide excellent estimates for thin membranes, but possibly lead to inaccurate material parameter estimates when the tissues become too thick or feature residual stretches.…”

“…US imaging is key to this setup, as it allows for measurements of the tissue deformation during bulge testing, a test that can now be performed inside the bioreactor. Previous studies have typically measured the tissue deformation during bulging using stereo camera setups [19,21,22,23,37,39] or advanced optical rigs [18,40], which are incompatible with the limited view of samples insides a bioreactor. In contrast, US is able to measure throughout the tissue cross-section, and can therefore be easily mounted on top of a bioreactor.…”

Application of the virtual fields method to the identification of the homogeneous anisotropic hardening parameters for advanced high strength steels

“…The identification procedure is usually implemented using a simple MATLAB ® program 1 and is very computationally efficient. So far, the VFM has been applied to elasticity, hyperelasticity, plasticity, and viscoplastictiy, for the characterization of 1 A commercial software platform integrating DIC and VFM is now available, www.matchidmbc.com 5 various materials (Fu et al, 2013;Grama et al, 2015;Grédiac and Pierron, 2006;Kim et al, 2012;Pierron et al, 2010). More work still needs to be done to extend the application of this method.…”