具有荷载缓和功能的双索张弦桁架结构静动力性能研究  

Research of static and dynamic performance on double-cable truss string structure with load relieving function

作　　者：刘国光[1] 武志玮[1] 

机构地区：[1]中国民航大学,天津300300

出　　处：《空间结构》2013年第3期39-44,共6页Spatial Structures

基　　金：国家自然科学基金资助项目(51178456);中国民航大学校级科研项目(2012KYE08)

摘　　要：荷载缓和装置能通过缓和构件内力、自动调整结构形状来保护结构.本文介绍了阻尼弹簧杆和一种新型荷载缓和装置在双索张弦桁架结构中的应用.通过有限元数值建模对构件内力和结构位移进行了理论计算,比较了7种荷载缓和布置方案对双索张弦桁架结构静力和动力性能的改进,总结了活荷载、水平地震荷载和弹性刚度系数对杆件内力和竖向位移的影响.结果表明,在下弦索设置新型荷载缓和装置时内力荷载缓和效果最佳,且荷载缓和效果与弹性刚度系数成反比;随着活荷载增加,抽样计算分析的单元呈现下弦杆内力减小,上弦杆、斜腹杆和下弦索内力增加的变化规律,采用荷载缓和装置后杆件内力增加幅度下降明显;在地震力作用下,荷载缓和装置通过增加结构变形降低了下弦索的应力非线性程度,避免结构发生倒塌破坏.Load relieving device is able to relieve the internal force of structural member and automatically adjust deformation of structure to achieve the function of self-protection. A new type of load relieving device and damping spring bar are introduced in this paper, which is applied in truss string structure with double cables. Member internal force and structural displacement are calculated theoretically through finite element method. Seven load relieving plans of improving the static and dynamic performances of truss string structure are compared. And the influences of live load, horizontal seismic load and elastic stiffness coefficient on load relieving effect are discussed. The results show that the most effective way of setting load relieving device is to use the new type of load relieving device in the cable, and the effect is inversely proportional to elastic stiffness coefficient. As the live load increasing, the internal force of lower chord bar is decreased, the internal forces of upper chord bar, slant strut and bottom truss are increased, and the changes of member internal force are decreased by using load relieving device. When the horizontal seismic load is applied on the structure, the stress non-linear condition of cable is relived by the increase of structural deformation, which is an effective method of avoiding structural collapse.

关 键 词：双索张弦桁架 荷载缓和体系 影响分析 静动力性能 

分 类 号：TU393.3[建筑科学—结构工程]