An anisotropic pseudo-elastic approach for modelling Mullins effect in fibrous biological materials

This paper presents a fully three-dimensional finite-strain formulation with a simple pseudo-elastic anisotropic model to reproduce the softening behavior that appears in soft biological fibred tissues (Mullins effect). This is an anisotropic extension of the pseudo-elastic model of Ogden and Roxburgh which was earlier proposed to describe the softening behavior of rubbers under large deformation. The model makes use of the concept of internal variables which provides a very general description of materials involving irreversible effects. Numerical simulations of uniaxial tests of several soft tissues are used to show the performance of the model in realistic situations. The computed results indicate that the proposed model is able to describe with enough accuracy the softening behavior of real soft biological tissues.