摘要
为提高大跨度空间结构的适用性,提出一种配置下拉减振索的大跨度空间结构,通过张紧的索体将结构体和固定体相连,可以减小结构在后期使用荷载下的竖向变形和振动。通过理论推导提出了反映配置下拉减振索的大跨度空间结构基本特征的无量纲参数R,以及中置及偏置索体的最小索力需求、结构内力和变形、自振频率和振幅形状曲线的计算方法,建议优先采取索体中置的布置方式以提高工作效率。实例分析结果发现,合理设计的配置下拉减振索的大跨度空间结构的振动加速度可减小至无索结构的50%以下,在后期使用荷载下的竖向变形可减小至无索结构的10%以下。通过有限元分析发现,索体松弛产生的动力效应将显著放大结构的竖向变形和加速度,故应对减振索进行适当张拉。最后提出配置下拉减振索的大跨度空间结构的设计流程,根据无索结构特性与控制目标的差异,先设定合理的R值再进行索体设计可显著提高设计效率。
To improve the applicability of large span spatial structures,a large span structure with tie-down vibration-reduction cable is proposed.By connecting the structure and the fixed body with tensioned cable,the vertical deformation and vibration of the structure under service load can be reduced.Through theoretical derivation,the dimensionless parameter R which represents the key characteristics of the large span structure with tie-down vibration-reduction cable is proposed,and the calculation methods of the minimum tension force of the cable,internal force,deformation,natural vibration frequency and amplitude shape curve of the structure with the cable placed in the middle or not in the middle are derived.It is suggested that the cable should be placed in the middle to improve the work efficiency.The case study shows that the vibration acceleration of structure can be reduced by more than 50%with the existing of tie-down cables,and the vertical deformation of the structure can be decreased by more than 90%.Through finite element analysis,it is found the dynamic effect caused by relaxed cable will significantly amplify the vertical displacement and the acceleration of the structure,so the cable needs to be properly tensioned.Finally,the design process of the structural system is proposed.According to the difference between the characteristics of the structure without cable and the performance objective,it will significantly improve the design efficiency to set a reasonable R value before the cable design.
作者
张龑华
盛平
冯鹏
甄伟
牛奔
ZHANG Yanhua;SHENG Ping;FENG Peng;ZHEN Wei;NIU Bena(Beijing Institute of Architectural Design,Beijing 100045,China;Department of Civil Engineering,Tsinghua University,Beijing 100084,China;MOE Key Laboratory of Civil Engineering Safety and Durability of China,Tsinghua University,Beijing 100084,China;Sinobo Gongti(Beijing)Commercial Operation Management Co.,Ltd,Beijing 100600,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2023年第4期32-41,共10页
Journal of Building Structures
基金
国家重点研发计划项目(2022YFC3801800)
北京市建筑设计研究院有限公司自主研发课题(2021-085)。
关键词
大跨度结构
索结构
下拉减振索
受力性能
振动舒适度
large span structure
cable structure
tie-down vibration-reduction cable
mechanical performance
vibration comfort
