火灾下钢梁悬索效应分析研究

为了研究高温下钢梁的大变形性能．本文使用ABAQUS有限元程序建立了分析模型。通过与有关的试验结果对比，验证了有限元分析程序计算的准确性和可靠性。在利用程序进行大量参数分析，包括跨度、应力比、边界条件、温度分布等参数分析的基础上,发现梁的水平支撑对其抗火承载力有很大的影响。为了在实际设计中应用钢梁的悬索效应，本文导出了计算钢梁变形和悬索力的简化计算方法。

Analysis of Catenary Action in Steel Beams under Fire Conditions

This paper investigates the large deflection behaviour of steel beams under fire conditions taking into consideration the effect of catenary action provided by the surrounding structures.After validating the capability of ABAQUS against available experimental results of fire tests,a numerical parametric study is conducted to investigate the effects of beam span,load ratio,uniform and non-uniform temperature distributions,different levels of axial and rotational end restraint and the effect of lateral torsional buckling.It is concluded that the existence of horizontal axial restraint can significantly affect a beam's survival temperature in fire.A simplified hand calculation method has been developed to model the beam large deflection behaviour at elevated temperatures,which may be adopted as a design calculation method.The proposed method can be used to predict the mid-span deflection and the catenary force of a restrained steel beam at elevated temperatures,which will be the main concerns of fire engineering design of the beam.