  We propose a continuum theory to model the Mullins effect, which is
ubiquitously observed in polymer composites. In the theory, the softening of
the materials during the stretching process is accounted for by considering the
delamination of polymer chains from nano-/micro-sized fillers, and the recovery
effect during the de-stretching process is due to the reattachment of the
polymer chains to nano-/micro-sized fillers. By incorporating the chain
entanglements, Log-Normal distribution of the mesh size in the network, etc.,
we can obtain a good agreement between our numerical calculation results and
existing experimental data. This physical theory can be easily adapted to meet
more practical needs and utilised in analysing mechanic properties of polymer
composites.
