Impact and residual after impact properties of carbon fiber/epoxy composites modified with carbon nanotubes

摘要

The effect of carbon nanotubes (CNTs) on the impact and after impact performance of woven carbon fiber/epoxy composites is investigated. Three nano-reinforced epoxy systems that differ in the CNT dispersion and functionalization are used as a matrix material. The composites are tested for the resistance to an out-of-plane low velocity impact, the residual compressive strength, the mode Ⅱ interlaminar fracture toughness and the interlaminar shear strength. The composite with the highest mode Ⅱ fracture toughness is found to be the best performing system in the compression test. The resin in this composite contains a network-like structure of CNTs. Nanotubes are found to have a dual effect on composite properties: (1) they improve the mode Ⅱ interlaminar fracture toughness and (with it) damage tolerance of a composite, but (2) they also make composites more susceptible to the onset of matrix cracks leading to a larger delamination area after impact.