轴心受压部分包裹混凝土十字形组合柱耐火性能研究  

Study on the Fire Resistance of Cross-Shaped Partially-Encased Composite Columns Subjected to Axial Compression

作　　者：王静峰[1,2] 孙彤 刘用 WANG Jingfeng;SUN Tong;LIU Yong(College of Civil Engineering,Hefei University of Technology,Hefei 230009,China;Anhui Advanced Steel Structure Technology and Industrialization Collaborative Innovation Center,Hefei University of Technology,Hefei 230009,China;Anhui Provincial Key Laboratory of Civil Engineering Structures and Materials,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学土木与水利工程学院,合肥230009 [2]合肥工业大学先进钢结构技术与产业化协同创新中心,合肥230009 [3]合肥工业大学土木工程结构与材料安徽省重点实验室,合肥230009

出　　处：《建筑钢结构进展》2023年第5期53-62,81,共11页Progress in Steel Building Structures

基　　金：国家自然科学基金(52108130);安徽省自然科学基金(2108085QE248);中央高校基本科研业务费专项资金(PA2021GDSK0078、JZ2021HGTA0158)。

摘　　要：部分包裹混凝土异形组合柱可避免室内凸柱问题的出现,但由于型钢翼缘外露和截面形状系数大,其抗火性能较差。为考察常用的十字形部分包裹混凝土组合(PEC)柱的耐火性能,采用ABAQUS有限元分析软件建立了轴压下十字形PEC柱的温度场及热力学分析模型。在已有相关试验数据验证模型可靠性的基础上,分析了十字形PEC柱的升温过程、受力机理和破坏模式,并与矩形PEC柱进行对比。之后详细研究了荷载比、长细比、截面尺寸和受火方式等对轴压下十字形PEC柱耐火性能的影响规律。结果表明:相比于矩形PEC柱,十字形PEC柱升温速度更快,耐火性能更差;十字形PEC柱耐火极限随荷载比、长细比的增加而显著降低,随截面尺寸的增大而显著提高;型钢翼缘受火对十字形PEC柱耐火极限的影响远大于混凝土表面受火的影响,但型钢翼缘不受火时,十字形PEC柱的耐火极限随混凝土受火面积的增大基本呈线性降低。基于参数分析给出了四周受火十字形PEC柱耐火极限的简化计算方法,计算结果与模拟结果吻合良好。研究结果可为异形PEC构件的抗火设计提供依据。The special-shaped partially-encased composite columns can avoid the problem of the indoor convex column,but its fire resistance is relatively low due to the exposed steel flange and large section factor.In order to investigate the fire resistance of commonly used cross-shaped partially-encased composite(PEC)columns,ABAQUS software was used to establish temperature field models and the thermodynamic models of cross-shaped PEC columns subjected to axial compression.After verifying the reliability of the models using the existing test data,the heating process,stress mechanism and failure mode of cross-shaped PEC columns were investigated,and compared with those of rectangular PEC columns.Afterwards,the influence of parameters such as load ratio,slendermess ratio,fire exposure types on the fire resistance of cross-shaped PEC columns subjected to axial compression were studied in details.The results indicated that the cross-shaped PEC column was heated up faster and exhibited lower fire resistance than that of rectangular PEC column.The fire resistance of cross-shaped PEC columns decreased with the increase of load ratio and slenderness ratio,but increased with the increase of cross-sectional size.The fire exposure types and steel flange had a much larger impact on the fire resistance of the crossshaped PEC column than that of the concrete surface.However,when the steel flange was not exposed to fire,the fire resistance of the cross-shaped PEC column decreased linearly with the increase of the fire exposure area of concrete.Based on the parametric study,a simplified calculation method was proposed for the fire resistance of the cross-shaped PEC columns subjected to surrounding fire,and the calculation results were in a good agreement with the simulation results.This research will provide a reference for the fire resistance design of special-shaped PEC members.

关 键 词：部分包裹混凝土组合柱 轴压 耐火性能 十字形 有限元分析 参数分析 

分 类 号：TU398[建筑科学—结构工程]