Material instabilities are precursors to phenomena such as shear bands and fracture. Therefore, numerical methods that are intended for failure simulation need to reproduce the onset of material instabilities with reasonable fidelity. Here the effectiveness of particle discretizations in reproducing of the onset of material instabilities is analyzed in two dimensions. For this purpose, a simpli...

The assessment of regional heart wall motion (local strain) can localize ischemic myocardial disease, evaluate myocardial viability, and identify impaired cardiac function due to hypertrophic or dilated cardiomyopathies. The objectives of this research were to develop and validate a technique known as hyperelastic warping for the measurement of local strains in the left ventricle from clinical ...

In isotropic finite elasticity, unlike in the linear elastic theory, a homogeneous Cauchy stress may be induced by non-homogeneous strains. To illustrate this, we identify compatible nonhomogeneous three-dimensional deformations producing a homogeneous Cauchy stress on a cuboid geometry, and provide an example of an isotropic hyperelastic material, which is not rank-one convex, and for which th...

BACKGROUND The biomechanical property of the periodontal ligament (PDL) is important in orthodontics and prosthodontics. The objective of this study was to evaluate the feasibility of measuring the biomechanical behavior of the periodontal ligament using micro-computed tomography (micro-CT). METHODS A custom-made apparatus measured the force and displacement of a porcine PDL specimen within t...

We present a method to determine elasto-mechanical properties of soft biological tissues, and a device able to perform the required measurements in-vivo. The device permits the controlled application of vacuum to small spots of organic tissue and registers the small deformation caused, during the whole measurement process. Deformation is measured with a vision based technique and the grabbed im...

The present study deals with the experimental analysis and mechanical modeling of tensile behavior of brain soft tissue. A transversely isotropic hyperelastic model recently proposed by Meaney (2003) is adopted and mathematically studied under uniaxial loading conditions. Material parameter estimates are obtained through tensile tests on porcine brain materials accounting for regional and direc...

Hyperelastic constitutive models are frequently used to characterize the stress-strain response of highly flexible materials. Literature surveys reveal most researchers report statistical quantities (e.g. mean and standard deviation) to describe and summarize hyperelastic coefficient values. However, statistical quantities are not appropriate for describing and summarizing coefficient values of...

In this paper, the problem of large pure bending deformations of membrane is considered. The membrane is a sector of torus with a closed cross-section. This membrane is called a curved tube for short. We consider the homogenous, incompressible, isotropic and hyperelastic material. The external load is a constant pressure and bending couples acting at the edges. The equilibrium equations reduce ...

Resume — A muscle-driven model of human lower face was established. Three pairs of facial mimic muscles (ZM Zygomaticus Major, LLS Levator Labii Superioris, LAO Levator Anguli Oris), subcutaneous soft tissues, skin and skull were reconstructed based on segmentation of subject-specific MRI data. FE simulation were performed to reproduce designed facial mimic positions (e.g. pronunciation of soun...