Study On Seismic Behavior Of Weakened Joints With End-plate Connection WEB Openings

Steel has high strength and good ductility,which is widely used in engineering practice.But steel members are prone to buckling,especially beam-column connections are prone to local instability and failure.Traditional beam-to-column end-plate connections are prone to cracks at the lower flange of the beam end.In order to improve the seismic performance of the joints,the method of locating the plastic hinges far from the beam-to-column connections can be adopted.Using the finite element software ABAQUS,on the basis of the experimental and research results of end-plate connection joints,the seismic performance of the joints under different weakening parameters is studied,and the reasonable range of weakening parameters to improve the seismic performance of the joints is obtained.Firstly,referring to the relevant data of end-plate connections at home and abroad,the weakened end-plate connections with openings are studied,and the ABAQUS finite element software is used to model the weakened end-plate connections.The reliability of the simulation is verified by comparing the experimental data with the model data.Then a model is created to weaken the opening of beam web,and the model data are obtained.Starting from the position of plastic hinge generation,hysteresis curve,skeleton curve,ductility and energy dissipation capacity,the seismic performance of ordinary beam-column end-plate connection specimens and weakened beam-column end-plate connection web opening specimens are compared and analyzed.The results show that the plastic hinges of weakened end-plate connections occur far away from the joints,and the seismic performance of weakened end-plate connections is better than that of ordinary end-plate connections.Secondly,a series of weakened specimens with different weakening parameters are designed for the weakened end-plate connections.Eleven specimens with different weakening parameters are selected as the research object,and the effects of the initial weakening distance L_n and the diameter D_n of the web opening on the seismic performance of the end-plate connections are analyzed.The results show that the location of the plastic hinge can be shifted outward by choosing appropriate weakening parameters,and the ultimate bearing capacity of the joints can be reduced within a certain range,and the ductility and energy dissipation capacity of the joints can be improved at the same time.Finally,the reasonable range of the initial weakening distance L_n and the diameter D_n of the web openings is obtained to improve the ductility and energy dissipation capacity of the joints,which will provide a basis for further research on the web weakening joints of beam-column end-plate connections.