Improving performance of GFRP/aluminum single lap joints using bolted/co-cured hybrid method

The present study proposes a bolted/co-cured hybrid joining method, and experimentally investigates the joint strength. The bolted/co-cured hybrid joints combine co-cured adhesive joints and bolted joints without damaging reinforcing fibers. The method allows for low scatter strength in static and fatigue loading for easily manufactured co-cured joints. Testing of the static tensile lap-shear and fatigue strengths is performed using aluminum alloy A5052-F and knit fabric glass epoxy composites. The results show that the hybrid joints have 1.84 times higher maximum shear strength and a quarter of the standard deviation compared with conventional co-cured joints. Furthermore, less stress concentration and undamaged glass fibers in the hybrid joints contribute to a much higher fatigue strength than that of the bolted joint.