Finite Element Analysis Of Composite Connections Between Square Composite Columns And Composite Beams With U-shaped Steel Section

Concrete-filled steel tubes have the strong points, such as high strength, good earthquake resistance, fast construction speed, good fire resistance and so on. Hence it is widely used in the buidlings. Composite beam with U-shape steel section is a kind of new composite member, which also possesses the adavantages of high load-carrying capacity and fire resistance. However, there are a few researches on this part. Specially, there is no research on the connection between square composite columns and composite beams with U-shape steel section. To promote the application of this kind of new composite beams, the static and hysteretic behavior of composite joint between square composite columns and composite beams with U-shape steel section is studied. The main contents are as follows:(1) Three-dimensional finite element model (FEM) is developed using the commercial finite element software ABAQUS. The exsisted experimental results are used to compare with the analytical results. The element type and material relationships are verified by comparing with the experiment results.(2) The finite element mdoel of connections with exterior diaphragms is developed. The typical speciemen subjected to static load and hysteretic loads is analyzed. The stress distribution of the components is studied in detail. Then the influence of the axial load ratio, width-to-thickness ratio, height of steel beam and reinforcement ratio of concrete slabs on the static behavior and the quasi static behavior of the connections with exterior diaphragms is analyzed.(3) The finite element mdoel of connections with interior diaphragms is developed. The mechanism of connections with interior diaphragms is studied in detail. Then the influence of axial load ratio, width-to-thickness ratio, height of steel beam and reinforcement ratio of concrete slabs on the static behavior and the quasi static behavior of connetions with interior diaphragms is investigated. At last, the comparison between connection with exterior diaphragm and connection with interior diaphragms is done.