\r孙国军，李晓辉，薛素铎，任竞赢\r
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AuthorsHTML:\r孙国军，李晓辉，薛素铎，任竞赢\r
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AuthorsListE:\rSun Guojun，Li Xiaohui，Xue Suduo，Ren Jingying\r
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AuthorsHTMLE:\rSun Guojun，Li Xiaohui，Xue Suduo，Ren Jingying\r
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Unit:\r北京工业大学建筑工程学院，北京 100124\r
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Unit_EngLish:\rCollege of Architecture and Civil Engineering，Beijing University of Technology，Beijing 100124，China\r
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Abstract_Chinese:\r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0.008 1～0.013 2 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．\r
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Abstract_English:\rThe 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 0.008 1 and 0.013 2. 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.\r
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Keyword_Chinese:Levy 型劲性支撑穹顶；自振特性；自振频率；阻尼比\r

Keywords_English:Levy-type rigid bracing dome；self-vibration characteristics；self-vibration frequency；damping ratio\r


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