高强度钢柱高温下承载力数值计算方法

为了对建筑结构中的高强度钢柱进行抗火设计和验算,研究了高强度钢柱在高温下的极限承载力数值计算方法。考虑温度对高强度钢材力学性能的影响,对常温下钢柱极限承载力计算的逆算单元长度法进行了延伸,编制了高温下高强度钢柱极限承载力计算程序。采用编制的程序对高强度钢柱在高温下的极限承载力进行了计算,将计算结果与有限元分析结果进行了比较,发现吻合较好。分析了高强度钢柱截面上残余应力的分布模式,残余应力大小和柱的初始几何缺陷对极限承载力的影响。研究表明：延伸的逆算单元长度法可以用于高强度钢柱高温下极限承载力计算,残余应力的分布模式和大小对高温下高强度钢柱的极限承载力影响很小,而初始几何缺陷对极限承载力的影响较大。

Numerical Method for Load Bearing Capacity of High Strength Steel Columns at Elevated Temperature

In order to make fire resistance design of high strength steel columns in building structures,the numerical calculation method on load bearing capacity of high strength steel columns at elevated temperature was investigated.By taking the mechanical property of high strength steel at elevated temperature into consideration,extension was made on the inverse calculation segment length method and the program to compute the load bearing capacity of high strength steel columns at elevated temperature was performed.The program was adopted to compute the load bearing capacity.The results obtained by the program and the finite element analysis were compared and good agreement had been found.The influence of magnitude,distribution mode of residual stress and initial geometry imperfection on ultimate load bearing capacity was analyzed by employing the program.It is shown that the extended method can be is shown used to calculate the load bearing capacity of high strength steel columns at elevated temperature;the magnitude and distribution mode of residual stress had little influence but the geometry imperfection have significant influence on ultimate load bearing capacity.