Experimental and Numerical Studies of a New Prefabricated Steel Frame Joint Without Field-Welding: Design and Static Performance

In this study, we explored the connection between the square steel tubular column and H-shaped steel beam in a high-rise prefabricated steel frame structure, where a new type of connection method was designed and researched. Based on the full-scale static experiments, the ultimate failure mechanism of the designed joint was analyzed for two configurations. The moment–rotation (M–R) curves and mechanical properties of both configurations were acquired and compared with that of a traditional welded joint having the same scale. The results showed that the failure modes of our proposed joint appeared as the failure of some sensitive regions that located in the connecting areas, accompanied by the out-of-plane buckling of the beam. Moreover, the rotational stiffness of our proposed joint was relatively lower than that of the traditional welded joint, but their differences in the flexural capacity were not obvious. The capacity of joint with the stiffening rib (JD-1) was slightly higher than that of the one without the stiffening rib (JD-2). Finally, a refined finite element modelling (FEM) was established and verified by result comparisons. Based on this, a further check of joint design was accordingly achieved by evaluating its integral stress development and concentration. The results illustrated that the connector stiffening can affect the stress distributions among all assembled components. In contrast, JD-2 showed a better performance in the uniformity of stress distribution by appropriately reducing the connecting stiffening.