A Universal Model for the Elastic, Inelastic and Active Behaviour of Soft Biological Tissues

Abstract

AbstractIn the present paper, we present a universal model for the elastic, inelastic and active behaviour of soft biological tissues. The model is based on generalised structural tensors representing linear combinations of the identity tensor and classical structural tensors associated with fibre directions. The anisotropic behaviour is controlled by the coefficients of these linear combinations appearing as weight factors. Changing these weight factors allows to model softening as well as active contraction. The framework of this unified approach is presented and specialised for typical soft tissue behaviour. In order to model preconditioning observed in cyclic mechanical loading, thermodynamically consistent evolution equations for these weight factors as internal variables are defined. Further, a formulation for active behaviour based on a functional representation of the weight factors is proposed. Finally, the model is illustrated in application to bladder tissue showing both noticeable preconditioning effects and active contractility (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)