Finite Element Simulation On Seismic Behavior Of Concrete-filled Steel Tube-reinforced Concrete Ring Beam Joint

These days, concrete-filled steel tube frameworks are widely used and increasingly concerned due to their advantages. However, it shows recently that the cracking of concrete-filled steel tube connection in some earthquakes was much more worse than what people have thought of. The study on seismic performance of concrete-filled steel tube column-to-steel beam connections all over the world, especially semi-rigid joints, is elementary for their different forms and complicated seismic performance. Fang XiaoDan and so on had researched the seismic performance of concrete-filled steel tube - reinforced concrete ring beam joint by the method of low-cycle reversed loading in 2002, the study outcome is good for reference. For absence of the finite element numerical simulation, we can't know each part's detail visually. To the question, on the conclusion of the other scholars, the paper created 3-D ANSYS modeling to analyze the concrete-filled steel tube-reinforced concrete ring beam joint. By rational meshing, we analyzed the stress of the joint accurately and compared with the experimental date. It can be conclude that: (1) The destruction of concrete-filled steel tube-reinforced concrete ring beam joint started by reinforced yield and Cracking Concrete at the contacts of framework beam and ring beam. (2) The steel pipe contacted with the ring beam has the greatest stress and most easily yield. We can see from the stress map that the maximum stress has emerged in the region through the loading. (3) The shear ring has not yet yield when the structure is damaged. It show that the strength of shear ring and the friction force of ring beam can withstanding the shearing force of concrete-filled steel tube and reinforced concrete ring beam. (4) The cracking of concrete ring beam begin at 0 degree and 180 degree. And then the concrete of the contact of ring beam and framework beam cracked. The concentration of concrete cracks is on about negative 25 degree and 25 degree. In the final the cracks spread on both sides of the ring beam. (5) We can see from the stress map of reinforced that the maximum stress of reinforcement is on the contacts of ring beam and framework beam, can enhance the component performance from increasing the dosage of reinforcement. (6) The maximum of slipping between the ring beam and the steel pipe is 4.5mm. (7) The hysteretic curve and skeleton curve of beam are good agreement with the experimental before the structure cracked, embodied a good seismic reflected. (8) Reasonable 3D finite element simulation can make up for the inadequate of test's observations and reveal the details which the test can't observe. It is a most effective way to understanding the stress changing.