Investigating the fatigue behaviour of quasi-isotropic pseudo-ductile thin-ply carbon/glass epoxy hybrid composites

This paper investigates the fatigue behaviour of pseudo-ductile Quasi-Isotropic (QI) interlayer hybrids with un-notched and open-hole configurations. Two different types QI were evaluated; HighC, carbon to glass thickness ratio 0.29, that is made thin-ply M46JB-carbon/epoxy Xstrand-glass/epoxy prepregs, LowC, 0.19, T300-carbon/epoxy standard-ply S-glass/epoxy prepregs. The hybrid configurations loaded at 4 Hz in tension–tension without any initial damage percentages pseudo-yield stress (σpy) which initiates. It was observed there no stiffness reduction, after 100,000 cycles, for a level 80 % 50 σpy laminates, respectively. By increasing 90 70 respectively, gradual reduction due appearance matrix cracking delamination but visible HighC. final failure more brittle happens lower number cycles HighC compared LowC. Different extents investigated laminates before sudden variables such as ply thickness, cyclic energy release rate interfacial fracture toughness.