Numerical Simulation of a Novel Welded Steel-Frame Joint Strengthened by Outer Corrugated Plates to Prevent Progressive Collapse

To effectively improve the anti-progressive collapse performance of steel frames, a novel reinforced joint, named the welded steel-frame joints strengthened by outer corrugated plates, was proposed. Firstly, the finite element model was validated according to previous test results. The anti-progressive collapse behavior of the novel reinforced joint was analyzed based on the validated modeling method. Effects of the central angle, corrugated plate thickness, corrugated plate width, length of circular arc, and welding angle on the anti-progressive collapse behavior of the reinforced joint were discussed. The design suggestions of the corrugated plates are presented. Finally, the effectiveness of the outer corrugated plates was further verified through one full-scale beam–column joint case and three plane frames. The results show that compared with the specimen strengthened by inner corrugated plates, the peak load and ultimate displacement of the joint strengthened by outer corrugated plates increased by 17.0% and 16.3%, respectively. Compared with the traditional full-scale beam–column joint, the load-bearing capacity and ultimate displacement of the joint strengthened by outer corrugated plates designed under reasonable suggestions significantly increased. Simply from the perspective of joints, the design suggestions were highly effective. Compared with the traditional plane steel-frame case with a total height of six floors, the bearing capacity and ultimate displacement of the plane steel-frame case strengthened by outer corrugated plates increased by 19.8% and 38.3%, respectively. The outer corrugated plates demonstrated a more pronounced effect in enhancing the collapse resistance for middle floors. Overall, the novel type of joint had a simple form and clear mechanical principles, which fully exerted the catenary capacity of the steel beams. The outer corrugated plates significantly improved the anti-progressive collapse performance of steel-frame structures.