Tensile properties and fatigue characteristics of hybrid composites with non-woven carbon tissue

The mechanical characteristics of hybrid composites with non-woven carbon tissue (NWCT) are investigated under static tensile and tension–tension fatigue loadings. The hybrid composites are made by stacking NWCT and CFRP prepregs. Thirteen kinds of composites are studied; i.e. NWCT composites, CFRP longitudinal [0]8, transverse [90]12, off-axis [45]12 and angle-ply [±45]3S, hybrid longitudinal ([0/0]4, [/0/0/]4), transverse ([90/90]6, [/90/90/]6), off-axis ([45/45]6, [/45/45/]6), and angle-ply ([+45/−45]3S, [/+45/−45/]3S). The symbol ‘/’ means that the NWCT is located between the CFRP layers. To estimate the stiffness of hybrid composites, the rule of mixtures is used. The effects of NWCT on the tension–tension fatigue life, the residual strength and stiffness of hybrid specimens are evaluated. The fatigue damage and failure mechanisms of the hybrid composites are analyzed with an optical microscope.