EXPERIMENTAL INVESTIGATION ON SEISMIC PERFORMANCE OF DOUBLE-STAGE-BEHAVIOR DRY-CONNECTED BEAM-TO-COLUMN JOINT

This study proposes a double-stage-behavior dry-connected beam-to-column joint (DADBJ), the key component of which is the rotational friction hinge (RFH) and the slitted buckling restrained steel plates (SBRSP). This novel joint features a double-stage mechanical behavior and repairable concentrated damage. In order to verify the rationality of DADBJ and reveal the mechanism of its double-stage mechanical behavior, a test specimen of DADBJ was designed and manufactured. The width of the preset slit of SBRSP was selected as the test variable. Two load cases are conducted under pseudo-static cyclic loading. The test results indicated that the proposed DADBJ achieves its expected double-stage mechanical behavior. In the first stage, the mechanical properties of the joint are provided by RFH. In the second stage, the mechanical properties of the nodes are jointly provided by RFH and SBRSP. The damage of DADBJ is concentrated at the core plates. By replacing the core plates of the SBRSP, the joint could be rapidly repaired with the performance equivalent to the original state. The width of the preset slit of SBRSP directly determines the activation displacement of the second stage of the DADBJ. The proposed theoretical formulas for the double-stage yield loads and the activation displacement of the second stage of the DADBJ are accurate. This research can provide a reference for the research and design of precast concrete frame structures and structures with multi-stage mechanical behaviors.