摘要
当设置SMA滑动摩擦阻尼器延展为自复位支撑时,连接的刚度可能影响支撑的力学性能,支撑可能会出现面内旋转和整体失稳。为检验由形状记忆合金滑动摩擦阻尼器和钢管串联而成的自复位支撑能否实现预期的滞回性能,针对支撑的轴向刚度、转动刚度和稳定性进行理论分析。通过往复加载试验获得了形状记忆合金棒的滞回曲线和摩擦机制的动摩擦系数。制作了1个1/3缩尺的支撑试件,并进行了拟静力试验和频率为1.0 Hz的动载试验,结果表明,轴向荷载作用下,支撑的荷载-位移滞回曲线呈光滑稳定的旗帜形,展示出优越的自复位能力和良好的耗能能力。基于滞回曲线,分析了支撑的承载力、割线刚度、耗散能量和等效黏滞阻尼比等滞回性能参数,发现其等效黏滞阻尼比可达16%。建立了支撑的三维有限元模型,数值模拟与试验数据吻合良好。通过数值模拟对钢管的轴向刚度予以分析,发现当钢管的轴向刚度降低至文中基准模型刚度的20%时,可能导致钢管屈服和支撑整体失稳。
When the SMA slip friction damper is extended as a self-centering brace,the stiffness of connecting member may affect the mechanical behavior of the brace,and the brace may experience in-plane rotation and overall instability.In order to check whether a type of self-centering brace,which is a serial combination of shape memory alloy slip friction damper and steel tube,can achieve the expected hysteresis performance.The axial stiffness,in-plane rotational stiffness and instability of brace were first described,and the corresponding theoretical analysis was carried out.In what followed,cyclic loading tests were conducted to obtain the hysteresis behavior of SMA bar and kinetic frictional coefficient of friction mechanism.One 1/3-scaled specimen was fabricated and subjected to the quasi-static loading test and dynamic loading test with a frequency of 1.0 Hz.The test results show that the load-displacement hysteresis curves of brace are smooth and stable in the shape of a flag under axial loading,which represents excellent self-centering ability and good damping capacity.Based on hysteresis curves,the hysteresis parameters of brace such as bearing capacity,secant stiffness,dissipated energy and equivalent viscous damping ratio,which can be up to 16%,were quantified.A three-dimensional finite element model of brace was established for numerical simulation and was validated to be in good agreement with the experimental data.Based on the calibrated model,a parametric analysis was conducted for the axial stiffness of the steel tube.The results indicate that when the axial stiffness of the steel tube is reduced to 20% of the reference model in this paper,it may cause yielding of the steel tube and global buckling of the brace.
作者
邱灿星
杨勇波
刘家旺
QIU Canxing;YANG Yongbo;LIU Jiawang(Key Laboratory of Urban Security and Disaster Engineering,China Ministry of Education,Beijing University of Technology,Beijing 100124,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2024年第1期139-150,共12页
Journal of Building Structures
基金
国家自然科学基金项目(52178267)。
关键词
自复位支撑
形状记忆合金
往复加载试验
数值模拟
滞回性能
self-centering brace
shape memory alloy
cyclic loading test
numerical simulation
hysteresis behavior
