自应力对圆钢管混凝土短柱轴压性能的影响机理及其预测模型  

Influence mechanism and prediction model of self-stress on axial compression performance of concrete-filled steel tube short column

作　　者：滕晓丹 蒙春贵 莫剑锋 孙辉煌 彭林欣[1,2,3] TENG Xiaodan;MENG Chungui;MO Jianfeng;SUN Huihuang;PENG Linxin(School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,Guangxi,China;Guangxi Key Laboratory of Engineering Disaster Prevention and Structural Safety,Guangxi University,Nanning 530004,Guangxi,China;Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education,Guangxi University,Nanning 530004,Guangxi,China;Guangxi Xinfazhan Communication Group Co.,Ltd,Nanning 530028,Guangxi,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学广西防灾减灾与工程安全重点实验室,广西南宁530004 [3]广西大学工程防灾与结构安全教育部重点实验室,广西南宁530004 [4]广西新发展交通集团有限公司,广西南宁530028

出　　处：《建筑科学与工程学报》2023年第6期58-71,共14页Journal of Architecture and Civil Engineering

基　　金：国家自然科学基金项目(11962001);国家重点研发计划项目(2019YFC1511103);中国博士后科学基金项目(2018M633298);广西自然科学基金项目(2018GXNSFBA138060)。

摘　　要：为研究自应力对圆钢管混凝土短柱轴压性能的影响机理,采用不同掺量的膨胀剂制备自应力混凝土,开展了12根圆钢管自应力混凝土短柱的轴心受压试验,分析了自应力对试件的破坏形态、荷载-位移曲线、极限承载力、破坏位移、荷载-应变曲线的影响。利用有限元软件ABAQUS建立钢管自应力混凝土轴心受压短柱有限元模型,模拟结果与试验结果吻合良好。进一步分析了自应力对试件极限承载力、钢管与混凝土的荷载分配、接触应力等方面的影响,并通过钢管与混凝土接触应力、混凝土纵向应力的变化阐明自应力对短柱轴压性能的影响机理。最后,基于统计分析的方法,对影响自应力的因素进行偏相关分析,提出自应力预测模型。结果表明:自应力不影响试件的破坏形态;试验中自应力对极限承载力的影响存在一个最佳水平,12%膨胀剂掺量组别的试件平均极限承载力最高;试件到达极限承载力对应的破坏位移随着自应力的增大而减小;自应力对荷载-位移、荷载-应变的变化趋势影响也不显著;提高混凝土强度、钢管强度、钢管壁厚均可提高试件的极限承载力。In order to study the influence mechanism of self-stress on the axial compression performance of concretefilled steel tube(CFST)short column,self-stressing concrete was prepared by using different dosages of expansion agents,and axial compression test of 12 self-stressing CFST short columns were carried out,the influences of selfstress on the failure mode,load-displacement curve,ultimate bearing capacity,failure displacement and load-strain curve of the specimens were analyzed.The self-stressing CFST axial compression short column finite element model(FEM)was established by using the finite element software ABAQUS,and the simulation results agree well with experiment results.The influences of self-stress on ultimate bearing capacity,load distribution between steel tube and concrete,contact stress and so on were further analyzed.The influence mechanism of self-stress on the axial compression performance of short columns was illustrated by the change of contact stress between steel tube and concrete,and longitudinal stress of concrete.Finally,based on the method of statistical analysis,the partial correlation analysis of the factors affecting the self-stress was carried out,and a self-stress prediction model was proposed.The results show that self-stress does not affect the failure form of the specimens,and the influence of self-stress on ultimate bearing capacity has an optimal level in the test,the average ultimate bearing capacity of the 12%expansion agent content group is the highest.The failure displacement corresponding to the specimens reaching the ultimate bearing capacity decreases with the increase of self-stress.The effect of self-stress on load-displacement and load-strain is not significant.Improving the concrete strength,steel tube strength and wall thickness can improve the ultimate bearing capacity of specimens.

关 键 词：钢管混凝土 膨胀剂 自应力 短柱 轴压性能 

分 类 号：TU398.9[建筑科学—结构工程]