Experimental study on exterior joint of damage control steel frame

This paper presents a damage control steel-frame-joint (DCSF joint). By setting a splice plate on the web of a beam end, a beam and a column are connected by high strength friction bolts, and the prestressed reinforcement in the beam can provide re-centering capacity for the joint. Under a small earthquake, high strength friction bolts provide the initial stiffness and flexural bearing capacity for the joint; under a medium earthquake, and the slip of a bolt rod in a bolt hole dissipates energy for the joint. Therefore, main structural members are protected from damage. In order to study the initial stiffness, damage characteristics, hysteretic behavior and re-centering capacity of the joint, four full-size specimens were designed and tested under cyclic loading. Considering the effects of different contact surfaces of splice plates, the pretension of prestressed reinforcement, and pre-tightening force of high strength bolts respectively, the experimental study shows that:the slip of a high strength bolt rod in a bolt hole can provide good energy dissipation ability for the joint; the prestressed reinforcement can reduce the residual deformation of the structure and provide re-centering capacity for the joint; when inter-story displacement angle reaches 2.4%, the damage was mainly concentrated in bolt rods and the extrusion area of bolt holes on a splice plate, no obvious damage was found in main structural members. The bearing capacity and energy dissipation capacity of the joint basically remains unchanged after replacing the splice plate. The results of the study show that DCSF joint can be popularized and applied in earthquake regions due to its good seismic performance and convenient construction process without site welding.