The Three-dimensional Nonlinear Finite Element Analysis Strengthening Of Concrete-filled Steel Tubularring Nodes Outside And Optimization Of Design Proposals

At present, the use of high-rise building of concrete-filled steel tubular structures more and more, but the concrete-filled steel tubular beam-column joints of the mechanical properties need further study. In this paper, finite element analysis software Ansys10.0 of concrete-filled steel tubular columns and steel beams to strengthen the connection node ring finite element simulation, through the finite element model of the 10 samples analyzed to enhance the width of annular plate, the thickness of pipe wall thickness, End-column axial force, load factors on the five ways to enhance the performance of annular plates by the impact force. Analysis of results showed that: With the Central Board of the increased width and thickness, the bearing capacity of the node area has significantly increased, indicating the strengthening of the annular plate width and thickness are affected by a major factor in our performance. With the increase in pipe wall thickness, indicating bearing capacity of steel pipe wall thickness on the impact of smaller nodes. Axial force in the Central Board under the stress value has increased, the axial force to the Central Board of stress "effect" in a smaller, so that we can not consider the axial force by the force of the node area performance. Through analysis of strengthening the Central Board of stress and strain distribution mechanism, to strengthen the ring in a one-way load, maximum stress and strain of 50% mainly concentrated in the 450 and the beam axis into the framework of on-board in-the-loop effect limited in scope, mainly concentrated in the region 450 of relatively small impact in other regions. Here annular plate radial stress and strain distribution of the ramp into a straight line, high stress and strain on the Central Regional Board of Internal. Therefore, the design of annular plates made of stress and strain in the ring plate section 450 into a straight-line assumption, this assumption is appropriate, safe design biased. In this paper, theoretical analysis, based on a node to optimize the design proposals, full account of shear webs of the node "confinement" effect of the weakening mechanism, the design method is simple, the structural design of concrete-filled steel tube has an important reference value.