A comparative study of pull-out performance of bolted joints in pultruded FRP with drilled holes or punched holes

In this study, we investigate the pull-out performance of bolted joints of pultruded fiber reinforced polymer (PFRP) profile specimens with drilled and punched holes, respectively, and investigate the effects of different resin matrices and different fiber directions on the pull-out performance of the bolted joints. The experiment results show that the pull-out performance of the bolted joints in the uni-axial polyurethane-based PFRP is better than that in the uni-axial unsaturated polyester resin-based PFRP. The pull-out capacity of bolted joints on the multi-axial PFRP specimens with drilled holes is better than that of bolted joints in the uni-axial PFRP specimens with drilled holes. The multi-axial fiber can effectively prevent longitudinal splitting of pultruded profiles and significantly improve their pull-out performance. The punching process has little impact on the pull-out performance of bolted joints in the uni-axial PFRP specimens. However, it greatly undermines the pull-out performance of the bolt hole of the multi-axial PFRP specimens. Finally, using the progressive damage analysis (PDA) model, and combined with the Hashin failure criteria, we establish a model by means of the C3D8R solid elements in ABAQUS to simulate the pull-out mechanical behavior of the bolted joints.