Mode‐ II Fracture and Residual Flexural Strength of MWCNT Modified E‐Glass/Epoxy Laminates

ABSTRACT In this study, three types of carboxyl‐functionalized multi‐walled carbon nanotubes (MWCNTs) were used to modify the mode‐II interlaminar fracture characteristics and residual bending resistance of E‐glass/epoxy composite laminates. The MWCNTs with different weight ratios were added into the matrix material, and the mode‐II interlaminar fracture toughness and the fracture propagation were investigated in accordance with the relevant ASTM standards. Fractured surfaces were inspected with SEM micrographs to justify the effects of MWCNTs on the mode‐II fracture of the laminate. The MWCNTs increased the adhesion of constituents in the laminates and obstructed the propagation of delamination. The MWCNTs enhanced mode‐II interlaminar fracture toughness and bending stiffness of the E‐glass/epoxy laminates. The short‐thin MWCNTs at 0.3 wt% increased mode‐II interlaminar fracture resistance of the laminate by about 2 times. The effects of long‐thin and long‐thick MWCNTs are quite low.