Hysteretic behavior of CFST column-steel beam bolted joints with external reinforcing diaphragm

• Published in: Journal of constructional steel research 2021-08, Vol.183, p.106729, Article 106729
• Main Authors: Ding, Fa-xing, Chen, Yang-bo, Wang, Liping, Pan, Zhi-cheng, Li, Cheng-yu, Yuan, Tao, Deng, Chao, Luo, Chen, Yan, Qi-wu, Liao, Chang-bin
• Format: Article
• Language: English
• Subjects: Bolted connection; Concrete-filled steel tube; External reinforcing diaphragm; Plastic energy dissipation; Rigid joint
• ISSN: 0143-974X; 1873-5983
• DOI: 10.1016/j.jcsr.2021.106729

In this study, three concrete-filled steel tubular (CFST) column-steel beam bolted joints with external reinforcing diaphragm were tested under cyclic loading using 1/2 scaled specimens, and the influence law of steel beam size and tie plate of high-strength bolts on the failure modes were discussed. The ABAQUS program was used to establish the three-dimensional solid finite element models of the joints, and the joint models were then verified by the test data. Taking the welded rigid joint with external reinforcing diaphragm as the benchmark, a connection detailing of bolted rigid joint and a method for classifying the joint were proposed. The stiffness, bearing capacity and plastic energy dissipation of the bolted joints with different structural detailing and reinforcing measures were compared and analyzed. The obtained results show that the bolted joints with external reinforcing diaphragm can be classified as semi-rigid joint. The stiffness and bearing capacity of the bolted joint can almost be equivalent with the welded rigid joint counterparts, when the external reinforcing diaphragm with stiffeners was connected to the steel beam using four rows of bolts and simultaneously setting web stiffeners at the beam ends. With the above configuration, the total plastic energy dissipation of the bolted joint is over 80% of that of the welded rigid joint counterpart, and the steel beam is found to be the main component contributing the plastic energy dissipation. [Display omitted] •Three CFST column-steel beam bolted joints with external reinforcing diaphragm were tested under low cyclic loading.•FE models of the bolted joints were developed and verified with test results.•Bolted joints with different reinforcing measures were compared and analyzed.•The total plastic energy dissipation of the optimized bolted joint could be comparable to the welded rigid joint.