Constitutive modeling of human skin allowing for anisotropy and growth

In this paper, a constitutive law for skin is proposed which possesses parameters that are more physiologically based than those used previously for skin modeling. The Arruda-Boyce hyperelastic constitutive law, previously used in its incompressible form with success to model elastomers in various deformation states, has been generalized for compressible or nearly incompressible materials and incorporated into a finite element code to model skin data from the literature. The physiologic basis of this law allows for the incorporation of additional physics, including anisotropic response and stress-assisted growth, in terms of skin constitution parameters such as fiber cross-link density and fiber length