【摘要】 为考察高温下异形柱与结构中相邻构件之间的相互作用对柱耐火性能的影响,建立了高温下端部受约束的混凝土异形柱数值分析模型。基于二维热分析矩形单元和三维梁单元编制了端部受约束的异形柱高温反应全过程分析程序。利用程序分析了轴向约束和转动约束对柱耐火性能的影响。结果表明:1)在升温过程中,轴向约束会产生较大的附加轴力。当轴向约束刚度较大时,附加轴力可达到常温时轴力的65%左右;2)转动约束可使柱耐火极限显著提高;3)无转动约束时,柱耐火极限随荷载偏心率的增大而减小;但有转动约束时,荷载偏心率对柱耐火极限的影响较小。更多还原

【Abstract】 The existing of adjoining members may influence the fire resistance of the heated columns with special-shaped cross section. In order to investigate this influence, this paper proposes a numerical model for end constrained columns with special-shaped cross section at elevated temperature. Using 2-dimensional thermal analysis rectangular elements and 3-dimensional beam elements, a full-process analytical program was developed for the behavior analysis of end constrained columns with special-shaped cross section subjected to fire, and the effects of axial constraint and rotational constraint on the fire resistance are analyzed. The results show: 1) axial constraint will introduce significant additional axial forces in concrete columns, which are approximately 65% of the axial forces at room temperature. 2) rotational constraint can significantly increase the fire resistance of columns with special-shaped cross section. 3) the fire resistance of columns without rotational restraint decreases significantly with an increasing of load eccentricity ratio, but the load eccentricity ratio has little influence on the fire resistance of columns with rotational constraint.更多还原