Impact properties of a new hybrid composite material made from woven carbon fibres plus flax fibres in an epoxy matrix

This study is the first to characterize the impact properties of a new hybrid composite made with woven carbon fibres plus unidirectional (i.e. Type A) or cross-ply (i.e. Type B) flax fibres in an epoxy matrix. A pendulum impact tester applied a range of impact energies (5-40 J) to a series composite plates, which were assessed using photographic, thermographic, and geometric techniques. The Type B composite had better impact performance vs the Type A as indicated by lower absorbed energies, higher penetration energy, smaller crack lengths, smaller indentation depths, smaller damage areas, lower temperature rises in the impact zone vs applied impact energy, and higher impact strength. Both the Type A and B hybrid composites had superior impact properties compared to pure flax fibre-reinforced epoxy composites reported in prior literature, suggesting that hybridization using synthetic and natural fibres can be done successfully.