This article investigates the effects of interface fiber orientation on the mode-I interlaminar fracture toughness, and the evolution of damage was monitored using acoustic emission technique. The results show that changing the interply fiber orientation improved the fracture toughness and delamination resistance significantly. The GIC initiation fracture toughness was found to increase by 87%, 71%, and 69% for 0°/45°, 0°/90°, and ±45° interfaces, respectively. The improvement in fracture toughness was attributed to the crack path diversion along the interply fiber orientation which offered more resistance to crack propagation. In addition, sentry function was also computed based on the correlation between the mechanical strain energy accumulated in the laminates, and the acoustic energy that propagates by fracture events made it possible to evaluate the delamination resistance. The results show that 0°/45° has high resistance to crack propagation followed by 0°/90°, ±45°, and 0°/0°. Finally, scanning electron microscopic analysis was used to determine the fracture surface in different interply fiber orientation of glass/epoxy laminates.
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