Tension-tension fatigue behavior of hybrid glass/carbon and carbon/carbon composites

This work investigates the quasi-static, low-cycle and fatigue behavior of hybrid glass/ultra-high modulus carbon (GC) and low modulus/ /high modulus carbon (CC) fiber composites. These pseudo-ductile unidirectional interlayer hybrids are a new type of composites whose potential is not yet fully understood, particularly under cyclic/fatigue loading. Different test methods (digital image correlation, video extensometer and thermal camera) were used to record the evolution of the strain, damage and temperature during loading. The results of quasi-static loading shown pseudo-ductile responses with multiple fractures for all the series. The CC specimens exhibited higher initial elastic modulus, ‘yield’ stress and strength, while the GC specimens showed the highest pseudo-ductile strain. Much higher capacity of CC to resist to fatigue loading was observed. In the GC specimens significant damage was accumulated during fatigue loading, when the damage evolution of multiple fractures in different layers developed to delamination between the glass and carbon layers.