In a recent paper, Peng et al. (2006, "An Anisotropic Hyperelastic Constitutive Model With Fiber-Matrix Interaction for the Human Annulus Fibrosis," ASME J. Appl. Mech., 73(5), pp. 815-824) developed an anisotropic hyperelastic constitutive model for the human annulus fibrosus in which fiber-matrix interaction plays a crucial role in simulating experimental observations reported in the literatu...

A constitutive model based on the continuum mechanics theory has been developed which represents interlamellar cohesion, regional variation of collagen fibril density, 3D anisotropy and both age-related viscoelastic and hyperelastic stiffening behaviour of the human cornea. Experimental data gathered from a number of previous studies on 48 ex vivo human cornea (inflation and shear tests) enable...

Constitutive equations for inelastic behavior of anisotropic materials have been a challenge for decades. Presented is a new spherocylindrical microplane constitutive model that meets this challenge for the inelastic fracturing behavior of orthotropic materials, and particularly the shale, which is transversely isotropic and is important for hydraulic fracturing (aka fracking) as well as many g...

This work defines an incompressible, hyperelastic theory of anisotropic soft materials at finite strains, which is tested by application to the experimental response of fiber-reinforced rubber materials. The experimental characterization is performed using a uniaxial testing device with optical measures of the deformation, using two different reinforcing materials on a ground rubber matrix. In ...

Rocks are far from being isotropic and elastic. Such simplifications in modeling the seismic response of real geological structures may lead to misinterpretations, or even worse, to overlooking useful information. It is useless to develop highly accurate modeling algorithms or to naively use amplitude information in inversion processes if the stress-strain relations are based on simplified rheo...

This research is based on experimental and numerical investigations of human lumbar spine. Human intervertebral discs usually exhibit highly anisotropic mechanical responses in a finite strain regime under physiological loading conditions. Human disc body units basically consist of a fluid filled cavity (nucleus pulposus) approximately at the disc center and surrounding tissue reinforced by col...

Stress and deformation analysis of the simple shear at finite strain of a strainhardening elastoplastic hollow circular cylinder is given. Both isotropic and anisotropic hardening models are considered. In the case of isotropic hardening, there is a closed form analytical solution. No normal stresses exist in this case. Purely kinematic hardening with a Mises-type yield condition is utilized as...

Sports-related concussion is a major public health problem in the United States that is estimated to occur in 1.6–3.8 million individuals annually, and is particularly common in football. Despite the significance and growing concerns about the potential long-term consequences of concussion, its biomechanical mechanisms are not fully understood. Since 1970’s computational head modeling has prove...