The Finite Element Study On Rectangular Concrete-filled Steel Tube Column-to-steel Beam Semi-rigid Connections

these days, rectangular concrete-filled steel tube framework is widely used and increasingly concerned due to its advantage. However, recently it shows that the damnification of rectangular concrete-filled steel tube connections, in some earthquakes 1, was much more worse than what people have thought of. All over the world, the experimental study on seismic performance of rectangular concrete-filled steel tube column-to-steel beam connections, especially semi-rigid connections, is elementary for their different forms and complicated seismic performance. The qusai-static experimental investigation into seismic behavior of rectangular concrete-filled steel tube column-to-steel beam semi-rigid connections was conducted. Two kinds of composite connections, namely stiffened end plate (SEP) connection and double split-tee plate (DST) connection, were tested under low-cycle reversed loading at the ends of columns. This study outcome is good for reference. For without finite element numerical simulation, at the same time, the numbers of the testing connections are limited and the model size is cut down therefore we can't know each part's detail visually. To the question, the paper created Ansys modeling to analyze the double split-tee plate (DST) connection. In Ansys, three-dimensional entity element is created in view of concrete crack, bolt connection and steel yield. Double split-tee plate (DST) connections, were simulate under low-cycle reversed loading at the ends of columns. By rational meshing, we analyzed the stress of the node accurately and compared with the experimental data. It can be concluded that: (l)Once steel yields the double split-tee plate(DST) connection will be destroyed. The double split-tee plate on the beam has large distortion and the bolts connect with concrete-filled steel tube become flexible. The stress of the screw caps, nuts and tees are is great. So the double split-tee plates and bolts are the key to control toughness and most load. (2)The result shows that the hysteretic circles of displacement are mild and not closed clearly. Double split-tee plate (DST) connections are fit for earthquake area to use.(3)The effect of axial compression ratio to the aclinic weight is huge and the horizontal carrying capacity increases with the ratio's increase. (4) Double split-tee plate (DST) connection's displacement framework curve has a long time augment after utmost load comes. It shows that DST connection has good rotational ductility.(5)According to three-dimensional finite unit simulation, we can find some details which cann't be displayed in experiment. Therefore, it is a...