非均匀火灾作用下方形钢管混凝土短柱剩余承载力研究

为研究非均匀火灾作用下方形钢管混凝土短柱剩余承载力,在合理采用钢材和混凝土本构关系的前提下,基于ABAQUS建立了火灾后钢管混凝土柱相继热力耦合分析模型,并依据试验数据验证模型有效性。在此基础上进行了单面、相对两面受火状态下方形钢管混凝土短柱的轴压工作机理分析和参数分析,结果表明:受火方式对构件温度场及受力机理影响较大;受火时间、截面边长、防火保护层厚度是构件非均匀受火后剩余承载力的主要影响参数。在工程常用范围内,回归了两种受火方式下方钢管轴压短柱剩余承载力影响系数计算公式,可为该类构件在火灾后的修复提供参考。

Residual lading capacity of concrete-filled square steel tube stub columns in non-uniform fires

This paper studies the residual capacity of concrete filled steel tubular short columns with square section in non-uniform fires. In terms of the proper constitutive relation of concrete and steel, a model of CFST columns coupling thermal and mechanical fields has been set up and the effectiveness of the models has also been verified by experimental data. Further, the mechanism and parameters of SCFST short columns under one side fire and opposite side fire are analyzed. The results show that the fire mode has a significant effect on components temperature field. Fire duration, length of cross section, covering thickness of fire protection are the main parameters which affect the residual capacity of components under non-uniform temperature field. Formulas with potential for engineering use are obtained by regression to calculate the residual capacity influence coefficient of CFST short columns under the two fire modes.