Levy型劲性支撑穹顶自振特性试验
|
摘要
劲性支撑穹顶结构是近年来在索穹顶结构的基础上提出来的一种新型结构体系,它把索穹顶结构下部的拉索全部用高强钢拉杆代替,既保留了索穹顶结构造型美观、构造轻盈等优点,同时又解决了柔性索穹顶在张拉成形过程中杆件定位难且由于无预应力而导致的无整体刚度的问题.为研究Levy型劲性支撑穹顶结构的自振特性,本文设计了一个6 m跨度的Levy型劲性支撑穹顶结构,并在试验场地张拉成型,同时测得实际内力与设计内力误差基本在1%以内.以这个试验模型为研究对象,采用激振器正弦激励法测定了该结构在初始预应力、满跨荷载以及半跨荷载3种荷载状态下的自振特性,得到了该结构在不同荷载状态下自振特性的变化规律.结果表明:该Levy型劲性支撑穹顶自振频率均较为密集,与索穹顶结构相似,验证了劲性支撑穹顶结构张拉成型的可能性与体系的合理性;不同状态下该Levy型劲性支撑穹顶自振频率理论值与试验值误差较小,均在±6%以内;在全跨荷载和半跨荷载分别作用下,低阶频率随荷载增加而增大,高阶频率随荷载增加反而有一定的降低趋势;该Levy型劲性支撑穹顶结构阻尼比基本在0.0081～0.0132之间,建议具有与该Levy型劲性支撑穹顶试验模型相似结构形式的Levy型劲性支撑穹顶在实际动力响应分析过程中阻尼比取0.01.
The rigid bracing dome is a new type of structural system proposed based on the cable dome in recent years. It replaces the cables in the lower part of the cable dome with high-strength steel tie rods,which not only retains the advantages of attractive appearance and lightness of the cable dome,but also overcomes the difficulty of bar positioning in the process of cable dome construction and forming. The problem that the structure has no integral stiffness due to no prestress of the bar is also solved. To investigate the self-vibration characteristics of the Levy-type rigid bracing dome,a Levy-type rigid bracing dome with a 6 m span was designed and stretched and formed at the test site.The error is within 1% between the measured actual internal force and the designed internal force. Taking this experimental model as the research object,the self-vibration characteristics at three kinds of load conditions(the initial prestress,full-span load and half-span load of structure) were measured by the sinusoidal excitation method. The variation of the self-vibration characteristics of the structure under different load conditions was obtained. Results indicate that the self-vibration frequency of the Levy-type rigid bracing dome was relatively dense,which is similar to the cable dome. This proves that the structural form is reasonable and can be formed by means of tensioning. The difference between the theoretical value of the Levy-type rigid bracing dome and the experimental value was within ±6% under different conditions. Under the condition of full-span load and half-span load respectively,the low-order frequency increases with the increase in the load,and the higher-order frequency decreases with the increase in the load. The damping ratio of the Levy-type rigid bracing dome was basically between 0.0081 and 0.0132. The recommended damping ratio should be 0.01 in the actual dynamic response analysis process when a structure has a similar structural form to the Levy-type rigid bracing dome test model.
The rigid bracing dome is a new type of structural system proposed based on the cable dome in recent years. It replaces the cables in the lower part of the cable dome with high-strength steel tie rods,which not only retains the advantages of attractive appearance and lightness of the cable dome,but also overcomes the difficulty of bar positioning in the process of cable dome construction and forming. The problem that the structure has no integral stiffness due to no prestress of the bar is also solved. To investigate the self-vibration characteristics of the Levy-type rigid bracing dome,a Levy-type rigid bracing dome with a 6 m span was designed and stretched and formed at the test site.The error is within 1% between the measured actual internal force and the designed internal force. Taking this experimental model as the research object,the self-vibration characteristics at three kinds of load conditions(the initial prestress,full-span load and half-span load of structure) were measured by the sinusoidal excitation method. The variation of the self-vibration characteristics of the structure under different load conditions was obtained. Results indicate that the self-vibration frequency of the Levy-type rigid bracing dome was relatively dense,which is similar to the cable dome. This proves that the structural form is reasonable and can be formed by means of tensioning. The difference between the theoretical value of the Levy-type rigid bracing dome and the experimental value was within ±6% under different conditions. Under the condition of full-span load and half-span load respectively,the low-order frequency increases with the increase in the load,and the higher-order frequency decreases with the increase in the load. The damping ratio of the Levy-type rigid bracing dome was basically between 0.0081 and 0.0132. The recommended damping ratio should be 0.01 in the actual dynamic response analysis process when a structure has a similar structural form to the Levy-type rigid bracing dome test model.
引文
[1]薛素铎,高占远,李雄彦,等.一种新型预应力空间结构:劲性支撑穹顶[J].空间结构,2013,19(1):1-7.Xue Suduo,Gao Zhanyuan,Li Xiongyan.A new prestressed spatial structure:Rigid bracing dome[J].Space Structures,2013,19(1):1-7(in Chinese).
[2]薛素铎,何永发,李雄彦,等.劲性支撑穹顶结构模态性能参数分析[J].世界地震工程,2015,31(1):1-7.Xue Suduo,He Yongfa,Li Xiongyan,et al.Modal characteristics parameter analysis of rigid bracing dome[J].World Seismic Engineering,2015,31(1):1-7(in Chinese).
[3]陈志华,郭云,李阳.弦支穹顶结构预应力及动力性能理论与实验研究[J].建筑结构,2004,34(5):42-45.Chen Zhihua,Guo Yun,Li Yang.Theoretical and experimental study on the prestress and dynamic performance of a string-supported dome[J].Building Structure,2004,34(5):42-45(in Chinese).
[4]张爱林,王冬梅,刘学春,等.2008奥运会羽毛球馆弦支穹顶结构模型动力特性试验及理论分析[J].建筑结构学报,2007,28(6):68-75.Zhang Ailin,Wang Dongmei,Liu Xuechun,et al.Dynamic performance experiment and theoretical analysis on the suspend-dome structure model of the badminton gymnasium for 2008 Olympic Games[J].Journal of Building Structure,2007,28(6):68-75(in Chinese).
[5]张晓燕.索穹顶结构的静自振特性研究[D].北京:清华大学土木水利学院,2004.Zhang Xiaoyan.Static and Dynamic Analysis of the Cable Dome[D].Beijing:School of Civil Engineering,Tsinghua University,2004(in Chinese).
[6]王振华.索穹顶与单层网壳组合的新型空间结构理论分析与试验研究[D].杭州:浙江大学建筑工程学院,2009.Wang Zhenhua.Theoretical and Experimental Research on a New Spatial Structure Composed of Cable Dome and Singlee-Layer Lattice Shell[D].Hangzhou:College of Civil Engineering and Architecture,Zhejiang University,2009(in Chinese).
[7]何永发,薛素铎,李雄彦,等.肋环形劲性支撑穹顶结构动力特性分析[C]//第15届空间结构学术会议论文集.上海,中国,2014:181-186.He Yongfa,Xue Suduo,Li Xiongyan,et al.Analysis of dynamic characteristics of ribbed elastic support dome structure[C]//Proceedings of the 15th Academic Conference on Space Structure.Shanghai,China,2014:181-186(in Chinese).
[8]包红泽.鸟巢型索穹顶结构的理论分析与试验研究[D].杭州:浙江大学建筑工程学院,2007.Bao Hongze.The Theoretical and Experimental Research of Biro-Nest Cable Dome[D].Hangzhou:College of Civil Engineering and Architecture,Zhejiang University,2007(in Chinese).
[9]刘晶波,杜修力.结构动力学[M].北京:机械工业出版社,2005.Liu Jingbo,Du Xiuli.Structural Dynamics[M].Beijing:China Machine Press,2005(in Chinese).
[10]李可娜,殷志祥.Kiewitt型弦支穹顶结构自振特性研究[J].空间结构,2011,17(1):21-26.Li Kena,Yin Zhixiang.Natural vibration characteristic of Kiewitt suspendome[J].Spatial Structure,2011,17(1):21-26(in Chinese).
[11]刘伟,高维成.单层短程线网壳结构模型试验研究[J].实验力学,2006,21(4):519-526.Liu Wei,Gao Weicheng.Experimental study on the model of single-layer short-range reticulated shell structure[J].Journal of Experimental Mechanics,2006,21(4):519-526(in Chinese).
[2]薛素铎,何永发,李雄彦,等.劲性支撑穹顶结构模态性能参数分析[J].世界地震工程,2015,31(1):1-7.Xue Suduo,He Yongfa,Li Xiongyan,et al.Modal characteristics parameter analysis of rigid bracing dome[J].World Seismic Engineering,2015,31(1):1-7(in Chinese).
[3]陈志华,郭云,李阳.弦支穹顶结构预应力及动力性能理论与实验研究[J].建筑结构,2004,34(5):42-45.Chen Zhihua,Guo Yun,Li Yang.Theoretical and experimental study on the prestress and dynamic performance of a string-supported dome[J].Building Structure,2004,34(5):42-45(in Chinese).
[4]张爱林,王冬梅,刘学春,等.2008奥运会羽毛球馆弦支穹顶结构模型动力特性试验及理论分析[J].建筑结构学报,2007,28(6):68-75.Zhang Ailin,Wang Dongmei,Liu Xuechun,et al.Dynamic performance experiment and theoretical analysis on the suspend-dome structure model of the badminton gymnasium for 2008 Olympic Games[J].Journal of Building Structure,2007,28(6):68-75(in Chinese).
[5]张晓燕.索穹顶结构的静自振特性研究[D].北京:清华大学土木水利学院,2004.Zhang Xiaoyan.Static and Dynamic Analysis of the Cable Dome[D].Beijing:School of Civil Engineering,Tsinghua University,2004(in Chinese).
[6]王振华.索穹顶与单层网壳组合的新型空间结构理论分析与试验研究[D].杭州:浙江大学建筑工程学院,2009.Wang Zhenhua.Theoretical and Experimental Research on a New Spatial Structure Composed of Cable Dome and Singlee-Layer Lattice Shell[D].Hangzhou:College of Civil Engineering and Architecture,Zhejiang University,2009(in Chinese).
[7]何永发,薛素铎,李雄彦,等.肋环形劲性支撑穹顶结构动力特性分析[C]//第15届空间结构学术会议论文集.上海,中国,2014:181-186.He Yongfa,Xue Suduo,Li Xiongyan,et al.Analysis of dynamic characteristics of ribbed elastic support dome structure[C]//Proceedings of the 15th Academic Conference on Space Structure.Shanghai,China,2014:181-186(in Chinese).
[8]包红泽.鸟巢型索穹顶结构的理论分析与试验研究[D].杭州:浙江大学建筑工程学院,2007.Bao Hongze.The Theoretical and Experimental Research of Biro-Nest Cable Dome[D].Hangzhou:College of Civil Engineering and Architecture,Zhejiang University,2007(in Chinese).
[9]刘晶波,杜修力.结构动力学[M].北京:机械工业出版社,2005.Liu Jingbo,Du Xiuli.Structural Dynamics[M].Beijing:China Machine Press,2005(in Chinese).
[10]李可娜,殷志祥.Kiewitt型弦支穹顶结构自振特性研究[J].空间结构,2011,17(1):21-26.Li Kena,Yin Zhixiang.Natural vibration characteristic of Kiewitt suspendome[J].Spatial Structure,2011,17(1):21-26(in Chinese).
[11]刘伟,高维成.单层短程线网壳结构模型试验研究[J].实验力学,2006,21(4):519-526.Liu Wei,Gao Weicheng.Experimental study on the model of single-layer short-range reticulated shell structure[J].Journal of Experimental Mechanics,2006,21(4):519-526(in Chinese).