Studyon Seismic Performance Of Bundled Lipped Channel-concrete Composite Wall And Beam-flange-strengthenedconnections

In recent years,the state has made great efforts to promote the assembly building,actively and steadily promote thestructural steel construction.bundled lipped channel-concrete composite wall is a new type of steel structure,which has a wide range of engineering application value and significant social & economic benefits.Currently,there is less experimental and theoretical research on concrete composite wall system.On the basis of previous research,the paper proposed wall beam wing edge enhanced node suitable for this structural system,striving to achieve better mechanical performance so as to guide the design and engineering application.As to the seismic performance of bundled lipped channel-concrete(BLC-C)composite wall and steel beam-flange-strengthenedconnections,low cyclic loading experiment was carried out with one vertical connection and three beam-flange-strengthenedend-plate connections.Through this experiment,both the effect of welding flange and the wall on vertical connection and the influence of reinforced flange and end-plate thickness on end-plate connection were researched.The failure mode,ultimate bearing capacity,hystereticbehavior,ductility and energy dissipation capacity were analyzed to evaluate the seismic behavior.Bothconnections showedgood load carrying capacity,satisfactory ductility and strong energy dissipation capacity;When the flange and the wall are not welded on the vertical connection,despite the increased ductility,the capacity was reduced and the seismic performance weakened;Bearing capacity and seismic performance of the end-plate connection were enhanced with the increase of the end-plate thickness,which had a great effect on the connection.After adding the board to the flange of beam about the end-plate connection,ultimate bearing capacity,ductility and stiffness were all increased to a certain extent,but energy dissipation capacity was decreased slightly.By enhancing the flange of beam,the plastic hinge can be formed effectively,thus achieving the seismic purpose of ‘strong connection,weak member'.Finite element model was set up by utilizing ANSYS finite element analysis software in line with the actual size of components in the experiment to carry out numerical simulation analysis.Systematic research was carried out for the node by comparing to the experiment with parametric analysis conducted for the dimension,and size,etc.regarding the bottom fitch on the flange.The result shows that the result of finite element modeling has a good agreement with experimental result and the hysteretic curve of various curves presents full spindle.The action of flitch lengthening obviously improves the energy-dissipating capacity of node,enhances the joint initial rigidity and effectively delays the yield and failure of nodes so that it's a node with better anti-seismic property.Overall,priority should be given to the selection of rib node between beam flange and end plate welding or the connected node of flange reinforced end plate.