Numerical study of the seismic performance of a double-hinge steel frame joint

As the strength of the rigid joints of steel frame structures affects their seismic performance, studies on improved steel joints have been conducted. In this study, a novel double-hinge steel frame joint that optimized the working mechanism of the traditional steel frame joint was developed. The design process of a double-hinge joint was proposed through theoretical analysis. Its reasonability was verified through a validated finite element analysis. Finally, the performance of the double-hinge joints in a steel frame structure was simulated to validate the feasibility of the joint in structures. The results indicate that compared with the single-hinge joint, the cover plate deformation and internal force decomposition of the novel double-hinge steel frame joint are more favorable for energy dissipation. When the slenderness ratio of the reducing area region for the cover plate is greater than 19, the hysteretic curve is plump, and the seismic performance is satisfactory. At the maximum loading displacement, the load and deformation patterns match well with the expected working mechanism. The reduction of the bearing capacity and the energy dissipation capacity is induced by the out-shift plastic hinge. The plastic deformation is concentrated on the T-shape cover plates. The earthquake-resilient function and the feasibility of the double-hinge joint are validated in overall structures. • A novel double-hinge joint to facilitate energy dissipation is presented. • The design process of a double-hinge joint is proposed through theoretical analysis. • The feasibility and reasonability of the double-hinge joint are verified.