Impact resistance of short carbon fibre-carbon nanotube-polymer matrix hybrid composites: A stochastic multiscale approach

A multiscale approach is used here to investigate the impact properties of carbon fibre/carbon nanotube-reinforced polymer. For this purpose, the mechanical properties of the carbon nanotubes (CNTs) are obtained by molecular dynamics simulations. Then, they are included in the polyethene matrix, and the mechanical properties of CNT-reinforced polyethene are computed using a stochastic approach. Considering the CNT-reinforced polyethene as the matrix, the effect of adding the carbon fibres on its mechanical properties is investigated in the next step. Finally, utilizing a stochastic method, the macro-scale mechanical properties of carbon fibre/carbon nanotube-reinforced polymer are computed. Thereafter, the impact test is applied on the models. The finite element method is used to investigate the mechanical and impact properties of representative volume elements. The effects of waviness, volume percentage and aspect ratio of the carbon fibre and CNT on the mechanical properties of the multiscale composite are evaluated. It is shown that reinforcing the polyethene matrix by carbon fibres and CNTs significantly increases its impact resistance. Adding 3% and 5% volume percentages of CNT into 3%-carbon fibre/polyethene and 5%-carbon fibre/polyethene respectively, resulted in 26% and 47% improvement in the impact resistance of the composite.