Abstract: Self-centering structure is a new type of resumable structure, which can effectively control the residual deformation after earthquake and can be restored after a little maintenance. In recent years, self-centering structure has become a hot spot in the field of seismic engineering. At present, self-centering structure dissipates seismic energy mainly in two ways:plastic deformation of metal or friction damper. However, the above two modes usually have a large reduction resistance, which puts forward higher requirements on the reset members and adversely affects the self-centering performance of the joints. How to reduce the reduction resistance is an important problem that needs to be solved for such structure.
Based on the above problem, a new type of self-centering concrete-filled square steel tubular column-steel beam joint with slotted energy dissipation plates is proposed. The reduction resistance of the joints can be effectively reduced by setting slots on the energy dissipation plates. The joints is mainly composed of square concrete-filled steel tube column, steel beam, cantilever beam, slotted energy dissipation plates, cover plates, shear plates and strands, etc. In order to explore the failure mode, seismic performance, selfcentering performance and energy dissipation capacity of the joints, finite element software ABAQUS was used to simulate and analyze the self-centering square concrete-filled steel tubular column-steel beam joints. The moment-angular hysteretic curves, bearing capacity and characteristic moment, single-cycle hysteretic energy dissipation and residual deformation were obtained. Five joints were designed to compare the influences of the number of slots, the width and thickness of energy dissipation plates and the prestress of strands on seismic performance of the joints.
The results show that under seismic behavior, the hysteretic curves show "double flags" shape, and the joints have good bearing capacity, self-centering capacity and energy dissipation capacity. The main components are basically in elastic and the energy dissipation plates have obvious plastic deformation under 4. 00% displacement angle, indicating that the joints can control the damage locally and reduce the plastic damage on main components. The more slots of energy dissipation plates, the worse energy dissipation capacity and the better self-centering performance. However, it has no significant influence on the bearing capacity and characteristic moment of the joints. With the increase of width and thickness of energy dissipation plates, the energy dissipation capacity increases, the self-centering capacity decreases, and the bearing capacity increases. With the increase of prestress in strands, the initial stiffness, bearing capacity and decompression moment are increased, and the self-centering capacity is enhanced, but the energy dissipation capacity is less affected.