On dissolution and reassembly of filamentary reinforcing networks in hyperelastic materials

We generalize a theory for modelling the scission and reforming of cross links in isotropic polymeric materials in order to treat anisotropic mechanical behaviour. Our focus is on materials in which elastic fibres are embedded in an elastic matrix. The fibres may have a different natural stress-free configuration than that of the matrix, e. g. the fibres may be initially crimped in the absence of load. The modelling process allows the fibres to dissolve as deformation proceeds and then to immediately reassemble in the current direction of maximum principal stretch. This results in softening, altered mechanical properties and the possibility of permanent set. We illustrate a rich variety of such mechanical behaviours in the context of uniaxial stretch. The phenomena illustrated have important implications for the influence of mechanical factors in the remodelling of fibrous soft matter including biological tissue.