Experimental Study And Theoretical Analysis Of Concrete Filled Steel Tubular Column-to-truss Through Bolts-end Plate Connections

Staggered truss framing system,characterized by economy,efficiency and practicality, has drawn wide attention in academic circles of home and abroad in recents years. The predecessor are few to the Concrete filled steel tube column and the truss node form research. It has the partition board node form and the outside partition board node form and so on. It is convenient when the partition board node applies in the column section big situation. The Outside partition board node needs enough big horizontal link board to guarantee the node intensity and is bigger than partition board in steel quantity. Through bolts-end plate connections node is one kind of new node form. This kind of node form has displayed the shop-welded fully and work site bolting construction way.It reduces the disadvantage factor which constructs to the node performance influence. Based on this, this article uses to the concrete filled square steel tubular column–to-truss through bolts-end plate connections node to conduct the corresponding research.It is for the purpose of designing and developing one kind of reasonable feasible node form and Providing the reference for the project practice.This article has designed two kind of different terminal plate thickness of the concrete filled square steel tubular column–to-truss through bolts-end plate connections node test sample. To research the hysteretic behavior, energy dissipation capacity, ductility, strength degeneration and rigidity degeneration of the two kind nodes, two kind nodes are tested under the constant axis force and reverse loads. The nonlinear finite element analysis is done to the nodes using software ANSYS at the same time. The results of finite element analysis coincide to the results of the experiments. Finally through different parameter node model misalignment finite element analysis,parametric analysis were conducted on the connections to investigate the influences of compression ratio, steel tube wall thickness, the concrete strength in the steel tube, the terminal plate form, Level and diameter of bolt.The experimental study indicate that terminal plate thickness is not big to the node supporting capacity influence. But with the terminal plate thickness's increase, the node ductility coefficient becomes smaller and the node consumes energy coefficient becomes smaller. The finite element analysis indicated that compression ratio and steel tube wall thickness are more important to the connections. The relative research achievements could be referenced in practical application.