火灾下钢梁弯扭屈曲临界温度的计算方法

摘要

Based on the calculation formulas of critical moment for global flexural-torsional buckling of steel beams considering the effect of transverse load,a new method is proposed to calculate the critical temperature for flexural-torsional buckling of steel beams in fire,through incorporating the reduction factor for steel elasticity modulus at elevated temperatures.It is shown that the theoretical values are quite close to the experimental data and meet the requirement of structural fire resistance design.%基于考虑横向荷载影响推导的钢梁整体失稳发生弯扭屈曲时临界弯矩的计算公式,引入高温下钢材的弹性模量随温度的折减系数,给出了火灾下钢梁整体失稳时临界温度的计算方法.研究表明,该方法计算结果与试验值吻合较好,满足结构抗火设计的精度要求.