Seismic behavior of prefabricated beam-column joint with π-shaped connector

An innovative beam-column π-shaped joint, which was suitable for the low-rise prefabricated lightweight steel composite structure, was proposed in this paper. Firstly, with consideration of the variables of the column type, bending stiffness ratio between the beam and π-shaped connector, π-limb length, perforated end plate thickness, and with or without web connecting plate, twelve π-shaped joint specimens were prepared and their seismic behavior was experimentally investigated in aspects of failure mode, hysteretic performances, ultimate moment, stiffness degradation, deformation capacity, energy dissipation capacity, and strain response. Then the numerical model of the π-shaped joint was established and validated with the test data, which facilitates the further investigation of the influence of the bending stiffness ratio, π-limb length, and perforated end plate thickness on the seismic performance of the π-shaped joint. The test results showed that the application of the CFST column could improve the ultimate moment, initial stiffness, and energy dissipation of the π-shaped joint compared to the SHS column. Meanwhile, the introduction of the web connecting plate could avoid the separation of beam and column, resulting in a significant improvement in the seismic performance of the π-shaped joint. The test and numerical results demonstrated that decreasing the bending stiffness ratio, increasing the π-limb length and perforated end plate thickness was beneficial to further improve the seismic behavior of the π-shaped joint, and their corresponding suggested values were also provided in the present study.