摘要
为了研究在低周往复荷载作用下结构尺寸对方钢管混凝土短柱抗震性能的影响,对6根方钢管混凝土短柱开展了水平往复加载试验,分析了截面尺寸对柱破坏形态、滞回曲线、骨架曲线以及不同抗震性能指标(如刚度退化、耗能能力、延性等)的影响,阐明了不同截面尺寸对柱名义抗剪强度的影响规律和机制,研究结果表明:不同截面尺寸的试件破坏形态基本相同,表现为柱底部钢管鼓曲、核心混凝土被压碎的破坏形态;当截面尺寸由200 mm增至600 mm时,在不同加载方向上,方钢管混凝土短柱名义抗剪强度分别下降了63.1%(59.8%),表现出显著的尺寸效应;随着截面尺寸增大,相对名义刚度与平均耗能系数呈降低趋势;JIN等提出的考虑尺寸效应的抗剪强度公式计算值与试验值吻合良好,说明考虑尺寸效应的方钢管混凝土柱抗剪承载力计算公式能够较为准确的预测其抗剪承载力。
In order to study the seismic performance of square concrete filled steel tubular(CFST)short columns,a total of 6 specimens with different cross-sectional sizes were tested under combined constant axial loading and cyclic lateral loading.The failure mode,hysteretic curves,skeleton curves and seismic performance indexes(e.g.stiffness degradation,energy dissipation,ductility,et al.)with different cross-section sizes were analyzed.Meanwhile,the nominal shear strength of specimens with different cross-section sizes was studied.The results indicate that the final failure modes,i.e.,the bulge formed a complete ring on each side and the core concrete crushed at the same location,are similar for all columns with different cross-sectional sizes.The decline of nominal shear strength can be observed obviously as the structural size increases,i.e.the nominal shear strength decreases by 63.1%and 59.8%as the cross-section size varies from 200 mm to 600 mm under two opposite loading directions,indicating an obvious size effect;the relative nominal stiffness and the average energy dissipation coefficient decrease with the increase of structural size.The predicted values of shear strength formula that considers the size effect agree well with the tested values,implying this formula can be used to evaluate the shear capacity of square CFST short columns.
作者
金浏
梁健
李冬
杜修力
JIN Liu;LIANG Jian;LI Dong;DU Xiu-li(The key laboratory of Urban Security and Disaster Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《工程力学》
EI
CSCD
北大核心
2023年第4期35-45,共11页
Engineering Mechanics
基金
国家重点研发项目(2018YFC1504302)
国家自然科学基金项目(51822801)。
关键词
方钢管混凝土短柱
尺寸效应
抗震性能
名义抗剪强度
试验研究
square CFST short column
size effect
seismic performance
nominal shear strength
experimental studies
