扭转约束对无防火保护钢柱抗火性能影响分析

Influence of Rotational Restraint on Fire-resistance of Non-fireproofing Steel Column

应用ANSYS软件计算了钢柱在标准升温模式下的温度场,然后利用ANSYS的耦合分析模块,将温度场导入结构分析,分析了不同约束下轴心受压钢柱在温度升高时的力学反应,同时考虑了荷载比以及长细比对不同约束钢柱抗火性能的影响。研究表明：扭转约束钢柱的抗火性能要优于柱端没有扭转约束的简支柱;当钢柱长细比系数在30以内时,扭转约束钢柱在压缩阶段可以继续承受一定的荷载。最后给出了高温下扭转约束钢柱计算长度的确定方法,可为钢结构抗火设计提供参考。

The temperature field of steel column under standard warming mode is calculated by using ANSYS program.Then the temperature field is inducted into structure analysis by using the coupling analysis module of ANSYS.The mechanical reaction of steel column with axial compress and warming under different rotational restraints is analyzed with consideration of load ratio and slenderness ratio.The research indicates that the fire-resistance performance of steel column with rotational resistance is better than that of simply-supported column with no rotational restraint.Steel column can bear more loads in compress stage when its slenderness is under 30.Method of determining calculation length of steel column under high temperature is presented,which is of reference to fire-resistance design of steel frame.