| Earthquake is a highly destructive natural disaster.Self-centering structures can minimize structural damage to buildings caused by earthquakes and achieve rapid recovery of structures after earthquakes,and have great research value in promoting the green development of buildings.This paper integrates the concept of recoverable structure with the concept of energy dissipation and designs a new crawler steel energy-dissipating self-centering steel frame beam-column joints,with the crawler steel sheet as the main energy dissipating component and the prestressed steel reinforcement providing the recovery force.Firstly,the joint construction,assembly method and the force transmission path were briefly described,and a series of relevant properties of the node were verified to confirm its theoretical feasibility.To ensure the validity of the numerical simulation,a self-centering steel frame beam-column joints with complete test data was selected and numerical calculations were carried out under low circumferential reciprocating loads using the finite element method,which are verified to be in general agreement with the test data.Secondly,a finite element model was established for the new energy-dissipating self-centering steel frame beam-column joints proposed in this paper to study the seismic performance indicators such as stiffness,residual deformation and energy dissipation capacity of the node.The results show that the new energy dissipating self-centering joints proposed in this paper have small residual deformation,good self-centering effect and significantly better energy dissipation capacity than conventional frame joints.The factors affecting the seismic performance of the new joints were also analyzed by transforming parameters,such as the initial prestressing stress of the prestressing steel and the thickness of the energy dissipation sheet of the tracked steel.From the numerical simulation,it can be seen that the increase in initial prestressing force can improve the joint stiffness and self-centering capacity,whereas reduce the energy dissipation capacity of the structure;appropriately increasing the thickness of the track steel energy dissipation sheet within a certain range can improve the energy dissipation capacity of the self-centering joint and increase the stiffness of the self-centering joint and its load capacity.Finally,the new energy-dissipating self-centering joints were applied to a four-storey steel frame structure for numerical simulations under seismic effect.The steel frame model with self-centering joints and conventional joints were established separately.The seismic time history analysis is carried out by inputting seismic waves.The results show that the base shear and residual deformation of the self-centering steel frame are reduced,and the goal of “repairability under giant earthquakes” can be achieved. |
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