摘要
为降低强震对传统钢筋混凝土框架结构梁柱节点的破坏水平,提升梁柱节点在震后的可修复性,设计了一种内置超弹性形状记忆合金(shape memory alloy,简称SMA)筋的新型自复位梁柱节点。基于对不同配筋构造形式和SMA筋不同配筋率等因素的考虑,设计制作了4个1/5缩尺比例梁柱节点并进行了拟静力试验。通过非接触全场应变测量系统(video image correlate⁃3d,简称VIC⁃3D)对低周往复加载作用下各节点塑性铰区的整体位移和应变进行了实时测摄,获得了相应的竖向位移和主应变全过程云图。对起裂阶段、裂缝发展阶段和自复位阶段3个阶段进行研究,对比分析了各节点的破坏过程以及耗能能力、位移延性、刚度退化和自复位等性能。试验结果表明:内置超弹性SMA筋可有效提升节点的滞回耗能和自复位性能,延缓塑性核心区混凝土的开裂,改善开裂后的损坏程度,提升节点的经济可修复性;一定范围内,增大SMA筋配筋率可有效延缓节点的刚度退化速度,但对节点的极限承载力和自复位性能的提升影响不大。
In order to reduce the damage level of traditional reinforced concrete frame structure beam-column joints caused by strong motion,and to improve the repair ability of beam-column joints after earthquakes,a new type of self-centering beam-column joint with superelastic shape memory alloy(SMA)bars is designed.Four 1/5-scale beam-column joints are designed and manufactured based on the consideration of different structure rein⁃forcement forms and different reinforcement ratio of SMA bars,and quasi-static tests are carried out.The whole displacement and strain value of each joint plastic hinge area under low-frequency cyclic loading are measured in real time,and the corresponding vertical displacement and principal strain cloud graphs in whole process are ob⁃tained by video image correlate-3d(VIC-3D)technology.The stages of cracks initiation,cracks development and self-centering are studied,and the failure process,energy dissipation capacity,displacement ductility,stiff⁃ness degradation and self-centering performance of the joints are also analyzed.The experimental results show that the built-in superelastic SMA bars can effectively improve the energy dissipation capacity and self-centering capability of the joint,delay the cracking of concrete in plastic core area,optimize the degree of damage after cracking,and improve the economic repair-ability of joints;Within a certain range,Increasing the reinforcement ratio of SMA bars can delay the stiffness degradation of joints,but it does not significantly affect the improve⁃ment of ultimate bearing capacity and self-centering performance.
作者
裴强
吴聪
胡顺彩
PEI Qiang;WU Cong;HU Shuncai(College of Architectural Engineering,Dalian University Dalian,116622,China)
出处
《振动．测试与诊断》
EI
CSCD
北大核心
2022年第4期756-763,828,共9页
Journal of Vibration,Measurement & Diagnosis
基金
国家自然科学基金资助项目(51878108)。
关键词
自复位
形状记忆合金
梁柱节点
拟静力试验
非接触全场应变测量系统
self-centering
shape memory alloy
beam-column joint
quasi-static test
video image correlate-3d(VIC-3D)technology
