开槽方钢管混凝土轴压短柱力学性能研究  

Mechanical behaviors of axially loaded square concrete-filled steel tube(CFST)stub columns with notch in steel tube

作　　者：李彪[1] 张经科 丁发兴[1,2] LI Biao;ZHANG Jingke;DING Faxing(School of Civil Engineering,Central South University,Changsha 410075,China;Engineering Technology Research Center for Prefabricated Construction Industrialization of Hunan Province,Changsha 410075,China;Hunan Airport Management Group Co,.Ltd.,Changsha 410137,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]湖南省装配式建筑工程技术研究中心,湖南长沙410075 [3]湖南省机场管理集团有限公司,湖南长沙410137

出　　处：《铁道科学与工程学报》2022年第4期1041-1051,共11页Journal of Railway Science and Engineering

基　　金：国家重点研发计划专项基金资助项目(2017YFC0703404);国家自然科学基金资助项目(51978664);湖南省自然科学杰出青年基金资助项目(2019JJ20029)。

摘　　要：工程实际中的钢管混凝土构件在材料缺陷、构造开槽、环境腐蚀等因素的影响下,外部钢管表面将产生影响其结构完整性和使用寿命的局部缺陷。为研究钢管开槽对钢管混凝土短柱轴压承载力和钢管约束作用的影响,开展开槽方钢管混凝土短柱轴压性能试验研究和有限元分析。试验采用机械开槽的方式模拟钢管局部缺陷,探讨中部横向开槽、中部纵向开槽、角部横向开槽、角部纵向开槽4种开槽方式对构件荷载-应变曲线和破坏模式的影响。研究结果表明:开槽试件因开槽方式不同表现为槽口的凸起或闭合,且不同开槽方式将不同程度地降低钢管约束作用,导致构件承载力发生不同程度的下降,其中以中部横向开槽试件承载力下降最明显。之后采用ABAQUS有限元软件建立开槽方钢管混凝土短柱轴压三维实体有限元模型,在试验验证的基础下建立足尺模型进行参数分析,探讨不同开槽方式对承载力和钢管形状约束系数的影响。分析结果表明,横向开槽算例承载力和钢管形状约束系数降低相对未开槽算例较为明显,而竖向开槽算例基本不变。通过考虑不同开槽方式下钢管形状约束系数的折减建立开槽方钢管混凝土轴压承载力实用计算公式,公式计算结果与试验结果、有限元结果均吻合较好,表明实用计算公式精度较高,可应用于工程实际中开槽钢管混凝土构件承载力的计算。In engineering practice, local imperfections that affect the structural integrity and service life couldexist in the steel tube surface of concrete-filled steel tubular(CFST) members under the influence of material defects, structural notch, environmental corrosion and other factors. The axial compression tests and finite analysis of notched CFST were conducted to study the influence on axial bearing capacity and restraining action of steel tube. Mechanical notching was used to simulate the local imperfections of steel tube, and the effects on load-strain curves and failure modes were investigated under four notching methods of horizontal and vertical notch located in corner and side plate, respectively. The results showed that the notches of the specimens are convex or closed under different notching methods, which would reduce the constraint effect of the steel tube and bearing capacity to varying degrees. Among which the bearing capacity of the specimens with horizontal notch in the side plate was the most obvious. After that, the ABAQUS finite element software was used to establish the three-dimensional solid finite element model of the notched square concrete-filled steel tube under axial compression. Based on the experimental verification, a series of full-size models was established for parameter analysis, and the influence of different notching methods on the bearing capacity and the constraint coefficient of steel tube shape was discussed. The analysis results show that the bearing capacity and shape constraint coefficient of the horizontal notched examples decrease more obviously than that of the intact examples, while that of vertical notched examples are basically unchanged. By considering the reduction of steel tube shape constraint coefficient under different notching modes, the practical calculation formula of notched concrete filled square steel tubes under axial compression was conducted. The calculation results agree well with the tests and the finite element results, which shows that practical

关 键 词：方钢管混凝土 开槽 有限元分析 轴压承载力 钢管形状约束系数 

分 类 号：TU375.3[建筑科学—结构工程]