Behavior of hybrid bonded/bolted GFRP single-lap joint under static tensile loading: An experimental and numerical study

The mechanical performance of the GFRP hybrid bonded/bolted single-lap joints under static tensile loading is experimentally and numerically investigated. Static loading tests considering the hybrid joints with single bolt, four bolts, and nine bolts were first conducted to study the failure process and modes of hybrid joints. Finite element (FE) analysis involving the material degradation and failure laws was also performed to reveal the joints' internal failure mechanism. Based on the verified FE analysis approach, the effects of plate thickness and bolt end distance on the failure capacity and strength of the hybrid joints were further studied, by conducting a numerical parametric analysis. Results indicate that, the loading process of the hybrid joints can be identified into two stages divided by the bonding failure. The failure patterns mainly include the plate slippage, the inclination of bolts, and the tensile fracture of GFRP plate, and their occurrences vary for the joints with different bolt numbers. Additionally, the rigidity and failure load of joint are also significantly affected by the bolt number. As the plate thickness increases, the ultimate capacity of joints would be improved, while the failure strength decreases. With the bolt end distance getting greater, the ultimate capacity/strength would increase. In general, the achievement of this research work can provide references for the design and further study of the GFRP hybrid joints in civil engineering applications.