An Anisotropic Visco-hyperelastic Model Predicting Short-term Strain-rate Dependent Response of Soft Tissues

INTRODUCTION Hyperelastic models for articular cartilage have been developed for decades [1, 2]. These models have some capacity in predicting the cartilage load response in compression, but can unlikely account for time dependent behavior of soft tissues in tension as the inherent viscoelasticity of the tissue has not been taken into account. This study aims at developing an anisotropic viscohyperelastic fibril reinforced model accounting for nonlinearities and viscoelasticity of both fibrillar and extracellular matrix of soft tissues. Considering the shortcomings associated with the hereditary integral-based viscoelastic formulations in predicting short term responses, especially under high loading rates, a viscous function with an explicit dependence on strain rate has been used in this model to predict the time dependent load response.