A Nonlinear Compressible Transversely-Isotropic Viscohyperelastic Constitutive Model of the Periodontal Ligament

The periodontal ligament may be treated as a transversely-isotropic viscohyperelastic fibre-reinforced compressible material which is subject to large deformations and has an essentially nonlinear behavior. Within these assumptions, a continuum constitutive model of the PDL was proposed recently [48], which involves a number of material parameters that have to be identified from experimental data. An optical motion analysis system was developed [26] to collect data on the deformation of the PDL. In the present paper, an advanced version of the model is suggested, which is based on the assumption of the existence of an additive strain-energy function dependent on a number of principal invariants. The sensitivity analysis of the material parameters is performed and a parameter identification technique is suggested.