Characterization of interface, tensile-shear, and vibration performance of AA2024-T351/PP composite stepped-lap joint

In comparison with conventional methods, a directly bonded joint often provides a more effective and reliable way to meet the requirements of sound structures in engineering applications. However, the joint interface, mechanical response, and vibration characteristics of a hot-press bonded hybrid structure between the short-glass fiber reinforced composite and high-strength Al alloy have been understudied so far. Still, very few configurations have been characterized, especially considering those involving stepped-lap joints. Therefore, the present work addresses the potential use of polymer-metal hybrid joints in a stepped-lap configuration as a lightweight material by examining the acquired characteristics of hot-pressing connection through the bonding properties and transient and residual vibrations. The obtained results reveal that the directly bonded interface has trustworthy conditions after the surface modification (laser ablation treatment) of the Al alloy by the physicochemical variation and improved surface roughness. Hereby, the hybrid joint shows a promising performance in the load-carrying capacity with a mean failure load of 2432 N. The failure is always initiated at the metal-polymer interface. The SEM investigations demonstrate the signs of interface plasticity through the polymer composite. Since the damping ratio obtained for the dissimilar joint is satisfactory, outcomes obtained from the passive vibration control are quite suitable.