Analysis On The Behaviors Of Concrete-Filled Double Skin Steel Tubular Column To Steel Beam Joint

Concrete-Filled Double Skin Steel Tubes Structure,(CFDST)as a new type of structure with broad development prospects,not only has the advantages of solid concrete-filled steel tube structure,but also surpasses the traditional solid concrete-filled steel tube structure in terms of large flexural bearing capacity,seismic performance and fire resistance.At present,achievements on CFDST joints research are not much.However,as the key part of the overall structure,especially in frame structures,the joint play a vital role to the integrity and stability of the structure when the structure is on the elastic-plastic stage after suffering from severe earthquakes.In this paper,under low cycle load,mechanical properties of CFDST beam-column joints in frame structures was studied through numerical simulation,the main contents and results are as follows:Steel girder node based on the literature of concrete-filled steel tube column experiment was studied,using ABAQUS software established the cores,high strength bolt-overhanging end plate connection square round hollow interlayer steel pipe concrete column-steel beam node under monotonic load and cycle load of finite element analysis model.The model considers the combination node how multiple nonlinear materials,contact with a few factors,select the suitable material constitutive relation model and the interaction between internal and external steel tube and sandwich concrete,the influence of such factors as meshing and solved the entity unit to solve the convergence problem,and through the comparison and analysis of the results of numerical simulation and experimental results verify the rationality of the model.Numerical analysis model is established by finite element software ABAQUS,carried out the node under the monotonic load and cyclic reciprocating load bearing performance of the whole process of analysis,obtained the combination node key parts and important components of the stress distribution,study its mechanical characteristics and working mechanism,in-depth analysis of stress distribution regularity of different component damage.Set square steel tube wall thickness,the axial compression ratio,whether the overhanging end plate thickness and stiffener is set to change parameters,the other set of circular hollow laminated core concrete filled steel tubular column and steel beam in high strength bolts-the static performance of overhanging end plate connection node,hysteresis,ductility and energy dissipation capacity performance four mechanics performance index are studied,such node is discussed in the mechanical properties change rule under the influence of the parameters.