Tensile and Flexural Behavior of CFRP-Reinforced Notched Aluminum Produced by Wet Layup and Vacuum Bagging

Notches and localized defects can substantially reduce the load-bearing capacity of aluminum components by creating stress concentrations that promote premature failure. Externally bonded CFRP reinforcement offers a lightweight approach for restoring load-carrying capacity in damaged aluminum components. Direct experimental comparisons of wet-layup and vacuum-bagged CFRP reinforcement for notched aluminum under both tensile and flexural loading remain limited. This study investigates the tensile and flexural behavior of notched 6061-T6511 aluminum specimens reinforced with woven carbon fiber-reinforced polymer (CFRP) using manual wet layup and vacuum bagging. Two- and four-ply reinforcement configurations were evaluated, with five specimens tested for each condition. All CFRP-reinforced configurations increased the mean nominal strength and apparent modulus relative to the untreated notched specimens. The wet-layup two-ply configuration provided the greatest strength recovery, increasing nominal tensile strength from 141.88 to 245.89 MPa and nominal flexural strength from 213.84 to 384.81 MPa, corresponding to improvements of approximately 73% and 80%, respectively. Vacuum-bagged specimens exhibited higher apparent tensile moduli than the corresponding wet-layup specimens but lower tensile and flexural strengths. The wet-layup four-ply configuration produced the highest apparent flexural modulus, whereas the vacuum-bagged four-ply configuration produced the highest apparent tensile modulus. Increasing the CFRP reinforcement from two to four plies consistently increased the apparent tensile and flexural moduli but produced limited or reduced nominal strength, depending on the processing method and loading condition. These findings show that CFRP reinforcement can restore a substantial portion of the strength and apparent stiffness lost due to notching and highlight the importance of selecting the processing method and ply count based on the required balance between strength and stiffness.