Nonlinear multiscale modelling of quasi-solid state behaviour of PET/MWCNT nanocomposites: 3D RVE-based approach

Nonlinear 3D RVE-based computational multiscale model for prediction of the quasi-solid state behaviour of PET/MWCNT nanocomposites is proposed in this work. The model links the time and length scale of representative morphology of the nanocomposite with the corresponding macroscopic scales via the numerical homogenisation. Finite Element simulations of the uniaxial extension of the nanocomposite near the glass transition show that the addition of MWCNTs leads to significant stiffening of PET. It is caused by an excellent reinforcing ability of the nanotubes, which on average are found to carry the load around two orders of magnitude larger than the matrix. A significant decrease of nanocomposite stresses with increasing processing temperature in its narrow range near the glass transition is also predicted by the model.