摘要
为研究球冠形脱空对椭圆钢管混凝土短柱轴压性能的影响,该文通过带球冠形脱空椭圆钢管混凝土试件的破坏形态、轴压承载力、初始刚度和延性等性能在球冠形脱空影响下的变化规律,揭示了带球冠形脱空缺陷椭圆钢管混凝土轴压短柱的截面应变分布和核心混凝土强度特征,最终基于脱空特征对椭圆核心混凝土约束状态的影响机理,提出截面约束分区模型,推导并验证了考虑球冠形脱空影响的椭圆钢管混凝土短柱的轴压承载力计算公式。研究发现:核心混凝土破碎和斜向剪切、钢管局部鼓曲与凹陷以及试件的整体弯曲破坏是带球冠形脱空椭圆钢管混凝土轴压短柱的主要破坏形态;脱空缺陷的存在将削弱椭圆钢管与核心混凝土的相互作用,进而降低其轴压承载力、初始刚度和延性。
In order to figure out the effect of spherical-cap gaps on the performance of the axially loaded elliptical concrete-filled steel tube(ECFST),this paper conducts an experimental study on the axially loaded ECFST columns with spherical-cap gaps(ECFST-SG).The development rules of the failure mode,axial compressive resistance,initial stiffness and ductility of ECFST-SG column under the influence of spherical-cap gap ratio are analyzed.The strain distribution at mid-height cross-section and strength feature of the core concrete are revealed respectively.According to the mechanism of gap imperfection on the confining stress of core concrete,the confining division theory of the core concrete section is proposed,and the calculation formulae for predicting the axial compressive resistance of ECFST-SG columns is deduced and validated.The results indicate that the failure modes of the axially loaded ECFST-SG columns mainly include crushing and shear failure of the core concrete,outward and inward buckling of the steel tube,and excessive lateral deflection of the overall specimen.The spherical-cap gap may weaken the interaction between the elliptical steel tube and the core concrete distinctly,hence the axial resistance,initial stiffness and ductility of ECFST stub column will be reduced.
作者
沈奇罕
王静峰
李景哲
SHEN Qi-han;WANG Jing-feng;LI Jing-zhe(College of Civil Engineering,Hefei University of Technology,Hefei 230009,China;Anhui Collaborative Innovation Center for Advanced Steel Structure Technology and Industrialization,Hefei 230009,China;Anhui Key Laboratory of Civil Engineering Structures and Materials,Hefei 230009,China)
出处
《工程力学》
EI
CSCD
北大核心
2022年第12期141-150,共10页
Engineering Mechanics
基金
国家自然科学基金项目(52108129)
中央高校基本科研业务费专项资金项目(JZ2021HGQA0249,JZ2021HGTA0156,PA2021GDSK0081)。
关键词
脱空缺陷
椭圆钢管混凝土
轴压试验
破坏模式
承载力计算方法
spherical-cap gap imperfection
elliptical concrete-filled steel tube
axial compression test
failure pattern
strength design formulae
作者简介
沈奇罕(1991−),男,安徽淮南市人,讲师,博士,主要从事钢结构与组合结构研究(E-mail:QihanShen667@hfut.edu.cn);通讯作者:王静峰(1976−),男,安徽合肥市人,教授,博士,院长,主要从事钢结构与组合结构研究(E-mail:jfwang008@163.com).李景哲(1996−),男,河南禹州市人,博士生,主要从事钢结构与组合结构研究(E-mail:2589657648@qq.com).
