Experimental and numerical investigation of single lap, joggle lap, and filler-enhanced joggle lap bonded joints in CFRP Composites

This study evaluates the performance of adhesively bonded single lap joints, joggle lap joints without filler, and joggle lap joints with gap filler, using unidirectional carbon fiber-reinforced vinyl ester composite adherends manufactured through the vacuum-assisted resin infusion method. Both experimental and numerical investigations were conducted, with single-lap shear tests performed to assess maximum load, displacement, and shear strength, and finite element analysis used to model stress distribution within the adhesive overlap layer. Results indicate that SLJ exhibited the highest shear strength, followed by JLJ with gap filler, and JLJ without gap filler. Failure analysis showed a complex fracture mechanism, with SLJ showing exposed fiber, and JLJ specimens, especially those with gap filler, displaying delamination and mixed-mode failure. The study demonstrates the importance of joint configuration on both strength and failure modes, offering insights into optimizing adhesive bonding in composite structures.