摘要
以远场类谐和地震动、近断层向前方向性地震动与近断层滑冲型地震动三类长周期地震动为研究对象,在分析长周期地震动最大瞬时输入能与SDOF体系最大位移响应相关性的基础上,提出瞬时输入能比的概念,对比分析探讨不同类型长周期地震动作用下结构的破坏模式;基于Hilbert-Huang变换,以某12层RC框架结构为例,分析长周期地震动作用下控制结构弹塑性地震响应的IMF分量,并对不同类型长周期地震动的瞬时能量曲线及累积能量曲线进行对比分析,在此基础上提出有效长周期地震动、有效峰值及能量梯度的概念,分别从频域与时域角度分析长周期地震动对高层结构的作用机理。结果表明:长周期地震动的有效峰值显著大于普通地震动,揭示了长周期地震动作用下高层结构的地震响应大于普通地震动的内在机理;能量梯度对比分析表明不同类型长周期地震动的能量释放特征差异显著,揭示了远场类谐和地震动的脉冲循环作用机理及近断层向前方向性地震动与近断层滑冲型地震动的脉冲冲击作用机理,其中,前者易使结构发生累积损伤破坏,后者易使结构发生首次超越破坏。
Three types of long-period ground motions including far-field harmonic-like ground motions,near-fault forward-directivity ground motions,and near-fault fling-step ground motions were selected as objects. Firstly,based on the analysis of correlation between the maximum instantaneous input energy of long-period ground motion and the maximum displacement response of a SDOF system,the concept of instantaneous input energy ratio was proposed,and the structural failure modes under different types of long-period ground motions were discussed. Then,one 12-layer RC frame structure was taken for example,and the controlled IMF components of long-period ground motions for the elastic-plastic seismic response were analyzed based on Hilbert-Huang Transform（ HHT）. Besides,the instantaneous energy curves and accumulative energy curves for different types of long-period ground motions were investigated. And on this basis,the concepts of valid longperiod ground motion,valid peak and energy gradient were proposed,and the action mechanisms of long-period ground motions on high-rise structures were studied from the perspectives of frequency and time domains,respectively. The results show that the valid peaks of long-period ground motions are larger than those of ordinary ground motions,and it reveals the internal mechanism which causes the seismic responses of high-rise structures under long-period ground motions are larger than those under ordinary ground motions; the analysis of energy gradients shows that the energy release characteristics of different types of long-period ground motions are obviously different,and it reveals the action mechanisms of long-period ground motions. For the far-field harmonic-like ground motion,it has the pulse cyclic action mechanism which is easy to cause the cumulative damage failure; for the near-fault forward-directivity ground motion and near-fault fling-step ground motion,they have the pulse impact action mechanism which is easy to cause the first exceed failure.
作者
王博
代慧娟
吴涛
刘伯权
WANG Bo;DAI Huijuan;WU Tao;LIU Boquan(School of Civil Engineering,Chang＇ an University,Xi＇ an 710061,China;School of Architecture and Civil Engineering,Xi＇ an University of Science and Technology,Xi＇ an 710054,)
出处
《振动与冲击》
EI
CSCD
北大核心
2018年第12期123-130,共8页
Journal of Vibration and Shock
基金
国家自然科学基金项目(51708037
51408483)
中国博士后科学基金面上资助项目(2017M610616)
陕西省博士后科研资助项目(2017BSHEDZZ111)
中央高校基本科研业务费专项资金资助项目(300102288111)
关键词
长周期地震动
高层结构
破坏模式
作用机理
弹塑性地震响应
long-period ground motion
high-rise structure
failure mode
action mechanism
elastic-plastic seismic response
