New Type Of Joints On The Stress Behavior Of Concrete-Filled Square Tubular Column To Steel-Beam

The concrete-filled steel tubular column can possesses advantages over both pure steel and concrete material, and have special properties, such as high-strength, good ductility, better seismic behavior, etc. It has been used more and more in high-rising structures recently. The performance of the column and beam connection is the key influenced factor on the whole structure. But the research on the connection between the concrete-filled square steel tubular column and steel beam is not perfect.Based on the analysis of past concrete-filled steel tube columns and steel beam connections, aimed at the problems, a new type connection which adapted to square concrete-filled steel tube called steel beam continuous through connection. In order to fully understand the performances of this new type connection, by using simulation and calculation of the ANSYS three-dimensional finite element program in this paper, three-dimensional entity element is established steel beam continuous through connection for the concrete-filled square steel tubular column and steel beam .The systematic analysis to this new type joint is carried, and mainly analyzable and fruits as follows:1. The new joint transmission mechanism is discussed, compared transmission mechanism between steel beam continuous through connection and steel beam u-through connection, the result shows that: because of the horizontal shear on the side of beam is directly transferred to the core concrete, the new type connection is not too much depended on binding force and friction force between concrete in the connection zone and tube wall, so the overall rigidity of the connection is improved.2. There are six different types of concrete-filled square steel tubular column-H beam joints to analyze under monotonic loading and cyclic loading, and precisely analyzed the regulation of stress distribution in the connection zone, destroy pattern of all connections, connection hysteretic loop performance, damping performance and bearing capability. Analysis showed that: dumbbell-type connection flexural strength is far higher than other nodes. The joint is damaged when a plastic hinge is showed outside the region, it has satisfied the seismic design of the "strong column, weak beam, strong node and weak bar" in the earthquake Design principles.3. The main factors which influenced the rigid of dumbbell joint are discussed, and confirmed influence discipline to the rigid of dumbbell joint by parameters. The result shows: in all the factors, beam height can affect most to node capability, and the rigid of the node is affected most by beam width. The core concrete has a great ability to improve the dumbbell node, and can influence rigid and capability a lot. By using concrete to improve node rigid, it will have a safe reserve while designing.