Hyper- and viscoelastic modeling of the ovine intervertebral disc tissue

Intervertebral disc (IVD) carries compressive loads and resists the tensile shear stress, produced during bending rotational movements. Hence, identifying its mechanical behavior has always encouraged researchers to propose various models for this tissue. Both viscoelastic hyperelastic have been observed regarding IVD. Therefore, study aims at mechanically characterizing tissue using existing hyper- constitutive further discuss best ones. Three stress relaxation tests were performed on ten ovine cervical IVD samples evaluate their behavior. Models with linear, quasi-linear, nonlinear implemented. For response, another test was carried out a load constant strain rate fit seven previously suggested our recorded data. All as uniaxial compression. Calculations made isotropy incompressibility assumptions. Results approved nonlinearity of tissue’s since linear predicted divergent responses different inputs. However, modified superposition theory, featuring time- strain-dependent function, most accurate model predict response levels. As hyperelasticity, Mooney-Rivlin, Yeoh, Veronda-Westmann fitted experimental data higher R2 values.