Theoretical Analysis On Bearing Capacity Of Joint Between Concrete-filled Square Steel Tubular Column And Composite Beam With U Shape Steel Plate Encased Concrete Based On The Damage Of Node Domain

Composite beam with U shape steel plate encased concrete is that U-shaped steel beam with outer flange which is cold bended into by steel plate is filled with concrete and combined with floor slab forming T cross section.Shear connectors such as barrier is set between U-shaped steel and concrete, guaranteeing the synergy of them, and improving the overall stiffness and strength of beam. However, the complexity of the nodes limited its development and application.This paper designes two new joints between concrete-filled square steel tubular column and composite beam with U shape steel plate encased concrete, namely in the form of negative moment reinforcement which some are through the column and in the form of negative moment reinforcement are not through the column. This paper uses ANSYS software define the failure mode of nodes under the action of static through theoretical analysis.The mechanics performance of node is researched under the monotonic load and cyclic reciprocating load based on node area damage, research has shown that under monotonic loading, the limit bearing capacity at beam end of the two joint with different structure forms has a little change.To make use of finite element analysis software ANSYS, the paper has an analysis of the composite joint on the limit bearing capacity at beam end, ductility and dissipation characteristics by changing parameter,including concrete intensity inside column, axial-load ratio of column and width of outer ring stiffeners of the joint. The results show that the column concrete strength has little effect on the limit bearing capacity of beam end, and with the increase of concrete strength, the limit bearing capacity of beam end presents little increase; Axial compression ratio is more noticeable on the ultimate bearing capacity of nodes at the beam end, and the greater the axial compression ratio, the smaller the node of the bearing capacity; The ultimate bearing capacity of reinforcement ring plate overhanging length on the beam end.