Static and fatigue tensile properties of carbon/glass hybrid fiber-reinforced epoxy composites

The static and fatigue tensile properties of high-strength polyacrylonitrile (PAN)-based carbon (IMS60) and electronic (E)-class glass (E-glass) hybrid fiber-reinforced epoxy matrix composites (HFRPs) were investigated. The fiber orientations of the HFRP specimens were set to unidirectional with [(0(IMS60))/(0(E-glass))]S (subscript S means symmetry and [(0(IMS60))/(0(E-glass))/(0(E-glass))/(0(IMS60))]), [(0(E-glass))/(0(IMS60))]S, [(0(E-glass))/(0(IMS60))2]S, [(0(E-glass))/(0(IMS60))3]S, [(0(E-glass))/(0(IMS60))5]S, [(0(E-glass))2/(0(IMS60))]S, [(0(E-glass))3/(0(IMS60))]S, and [(0(E-glass))5/(0(IMS60))]S. Under static loading for the [(0(IMS60))/(0(E-glass))]S, [(0(E-glass))/(0(IMS60))]S, [(0(E-glass))/(0(IMS60))2]S, [(0(E-glass))/(0(IMS60))3]S, and [(0(E-glass))/(0(IMS60))5]S HFRP specimens, the stress applied to the specimen was almost linearly proportional to the strain until failure. However, the tensile stress–strain curves of the [(0(E-glass))2/(0(IMS60))]S, [(0(E-glass))3/(0(IMS60))]S, and [(0(E-glass))5/(0(IMS60))]S HFRP specimens had a complicated shape (jagged trace). The Weibull statistical distributions of the tensile strength values were also examined. The Weibull moduli for the [(0(E-glass))/(0(IMS60))]S, [(0(E-glass))/(0(IMS60))2]S, [(0(E-glass))/(0(IMS60))3]S, [(0(E-glass))/(0(IMS60))5]S, [(0(E-glass))2/(0(IMS60))]S, [(0(E-glass))3/(0(IMS60))]S, and [(0(E-glass))5/(0(IMS60))]S HFRP specimens were higher than those for the mono carbon fiber-reinforced epoxy (CFRP) and glass fiber-reinforced epoxy (GFRP) specimens. Under fatigue loading, the fatigue properties of the HFRP specimens showed CFRP-dominant behaviour at high stress levels and GFRP-dominant behaviour at low stress levels. The fatigue properties of the HFRP specimens increased with increasing volume fraction of CFRP in the following order: ([(0(E-glass))/(0(IMS60))5]S > [(0(E-glass))/(0(IMS60))3]S > [(0(E-glass))/(0(IMS60))2]S > [(0(IMS60))/(0(E-glass))]S > [(0(E-glass))/(0(IMS60))]S > [(0(E-glass))2/(0(IMS60))]S > [(0(E-glass))3/(0(IMS60))]S > [(0(E-glass))5/(0(IMS60))]S).