高温对管桁架节点承载力的影响

The effect of temperature on bearing capability of tubular joint

用大型有限元分析程序ANSYS对不同温度下圆管桁架T形节点的极限承载力进行了分析。分析计算时,充分考虑了高温引起材料性能衰退的材料非线性以及大变形效应的几何非线性,其中,钢材力学和物理性能参数随温度的降低系数按照在结构抗火方面应用广泛的欧洲规范(EUROCODE 3)采用。首先,进行了节点模型在常温下的极限承载力计算,并将计算结果与我国现行规范方法的计算结果进行比较,验证了所采用ANSYS计算方法的正确性,在此基础上进行高温计算。通过分析,得出不同温度下节点的极限承载力和最大位移,并定量给出节点极限承载力随温度的升高而降低的趋势和变化规律,总结了高温下节点温度及相应极限承载力近似线性的相关关系。

The bearing capability of T-shape circular tubular joint under different temperature has been analyzed by ANSYS. In the process of computation, material nonlinear behavior and geometry nonlinear behavior caused by temperature are taken into account thoroughly. The coefficient that material behavior decrease at high temperature relative to ambient is used according to EUROCODE 3 which is widely applied in fire resisting research in the world. The bearing capability of tubular joint at ambient is computed first, and the results are compared with those calculated by current cede in our country, which validates the ANSYS method used in this paper, and based on this, the computation at high temperature is carried out. By analysis, the bearing capability and maximum displacement at different temperature are obtained, the rule that bearing capability decreases with elevated temperature is presented quantitatively. The approximately linear relationship between temperature and bearing capability is concluded.