钢管混凝土节点抗弯刚度非线性分析

NONLINEAR ANALYSIS ON FLEXURAL RIGIDITY OF THE CFST OUT STIFFENING RING JOINT

目前,对钢管混凝土节点刚性的研究还处于定性分析阶段,尚无定量分析的相关成果。为此,利用有限元软件ANSYS,建立钢管混凝土外加强环式节点的三维非线性有限元模型。以环板宽度、环板厚度、柱径、柱壁厚度、梁高以及轴压比等为参数,采用单因素法和正交设计法,对影响节点抗弯刚度的因素进行分析,在此基础上提出节点抗弯刚度的计算公式,并对节点刚性进行分析,得到各有关因素对节点刚度的影响规律:1)随着环板宽度、钢管壁厚等增加,相对刚度-K呈线性增加;2)柱管直径与相对刚度-K为负指数关系;3)梁高变化对相对刚度-K没有影响;4)在轴压比超过0.5时,相对刚度-K有较大程度的下降。另外,对外加强环式节点,采用EC3提出的节点分类准则进行抗弯刚性分析,当按所提出的公式计算得到的节点刚度值大于8时,可以满足刚性要求。

Nowadays the research on the concrete filled steel tubular （CFST） joint rigidity is at the stage of qualitative analysis, but no achievements of quantitative analysis have been gained in this field yet. So the 3-d nonlinear finite element model of CFST out stiffening ring joint is established supported by the large-scale commercial finite element software. Taking ring plate width and depth, column diameter, depth of column wall, beam height as well as axial compression ratio as the main parameters, applying single factor way and orthogonal design method, the joint rigidity is analyzed and its calculation formula is put forward based on the analyses of the above factors able to affect the joint rigidity. The regularity of every factor affecting the joint rigidity is got： 1） Relative rigidity K is linearly increased as the ring plate width and depth of steel tubular wall added, 2） Tubular diameter has negative exponent relationship with the relative rigidity K , 3） Beam height change opposes no effect to the relative rigidity K , 4） The relative rigidity K is largely decreased when axial compression ratio more than 0.5. If the joint classification standard in EC3 is used for the out stiffening ring joint studied in this paper classification standard in the EC3, the joint rigidity value gained from the above posed formula shall be larger than 8, which can meet the rigidity requirement.