Fracture toughness of epoxy/multi-walled carbon nanotube nano-composites under bending and shear loading conditions

► Mode I and mode II fracture tests were conducted on epoxy/MWCNT nano-composites. ► Addition of MWCNT to epoxy increased both KIc and KIIc of nano-composites. ► The improvement in KIIc was more pronounced than in KIc. ► Mode I and mode II fracture surfaces were studied by scanning electron microscopy.