火灾下受轴向荷载钢柱的屈曲温度预测

根据欧洲规范,钢柱屈曲温度可采用解析法或简单的封闭方程进行估算。为此研究两种计算方法的精确度和局限性,对文献中高温下钢柱的试验数据进行对比。两种方法的预测结果都与适当利用系数的试验结果相符,与利用系数较高(μ0>0.83)或较低(μ0<0.16)的试验结果不符。简单方程的工作特性因素的均值为0.949,协方差为0.016,能够通过极值分布来描述。解析法的工作特性因素的均值为1.018,协方差为0.013,能够通过正态分布、伽马分布或对数正态分布来描述。

Predictability of Buckling Temperature of Axially Loaded Steel Columns in Fire

In current Eurocode,the buckling temperature of steel columns can be calculated by either using an analytical approach or using a simple closed-form equation.This paper investigates the accuracy and limitations of those two calculation approaches.Test data on steel columns at elevated temperature reported in literature are used for comparison.The two approaches are found to give acceptable prediction for tests with moderate utilization factor,and unacceptable prediction for tests with either high utilization factor(μ0>0.83)or low utilization factor(μ0<0.16). The professional factor for the simple equation has a mean of 0.949and a COV of 0.016,and can be best described by an extreme value distribution.The professional factor for the analytical approach has a mean of 1.018and a COV of 0.013,and can be well described by either a normal,gamma or lognormal distribution.