Seismic Behavior Of Steel Moment Connections With Single-Sided Engery Dissipating L-stubs Can Be Repaired Quickly After Earthquake

The performance of the steel frame beam-column joints directly affects the bearing capacity and stability of the overall structure.The traditional all-welded joints and bolt-welded hybrid joints did not show expectations due to the brittle fracture of the welds in the Northridge earthquake in the United States and the Hanshin earthquake in Japan Although the reinforced and weakened nodes improved for the above problems can move the plastic hinge outward,the repair of the structure will be very difficult;some nodes proposed based on the concept of recoverable functional structure have complex structures,Construction difficulties and other disadvantages.Therefore,the search for a low-cost,simple construction,superior seismic performance,and quick repair of steel frame beam-column connection nodes has become the focus of research.In this research,combined with the concept of buckling constraints and recoverable functional structures,a new type of steel frame beam-column joints that can be quickly repaired after an earthquake is proposed.In this research,11 sets of full-scale joint specimens are designed and produced.The failure mode,hysteresis curve,skeleton curve,energy dissipation capacity of the joint are studied through low-cycle reciprocating loading test,and the cutting process of the weakened section of the L-shaped plate is discussed.The influence of the test loading system and the presence or absence of buckling restraint cover on its seismic performance.The test results show that the node proposed in this paper can control the damage in the weakened area of the L-shaped plate,and the structure function can be quickly restored by replacing the damaged L-shaped plate after the earthquake;the experiment with reliable processing quality and anti-buckling restraint mechanism The plastic corners of the pieces are all more than 5%,which can meet the requirements of the Chinese standard "Code for Seismic Design of Buildings"GB50011-2010(2016)and the American Code for Seismic Design of Steel Structures for bending frame joints.Using ABAQUS finite element analysis software to model and analyze the nodes,the deformation of the numerical simulation results,the stress distribution cloud diagram,etc.were compared with the test to verify the correctness of the finite element model.The effects of parameters such as the length of the weakened section of the L-shaped plate,the thickness of the anti-buckling constrained cover plate,and the depth of the weakened section of the L-shaped plate on the joint performance are further explored.Finally,the strength design method for this node is proposed and the value range of the key parameters of the node design is given.The strength of the node obtained by this calculation method is in good agreement with the experimental value,which can be used as the design basis of the node.The testing described herein made use of technology and products developed and owned by Simpson Strong-Tie Company Inc.Simpson Strong-Tie Company Inc.is not affiliated with the author of this paper,and has not authorized,sponsored,or endorsed the authors of this paper in any way.This testing does not conform to the detailing requirements as set forth by Simpson Strong-Tie in AISC 358-16,Chapter 12.Therefore,the findings are those of the researchers and not Simpson Strong-Tie;nor do they reflect the performance of Simpson Strong-Tie' s proprietary Yield-Link technology when properly detailed.