【作者】 孙晓骥；

【导师】 王秀丽；

【作者基本信息】 兰州理工大学 ， 结构工程， 2007， 硕士

【摘要】 弦支穹顶(suspendome)是一种新型复合空间结构体系。它运用张拉整体思想，将单层网壳和索穹顶巧妙的结合起来，并综合了二者各自的优点，可以实现更加经济、合理地覆盖更大的空间，是一种富有生命力的新型结构体系。本文以凯威特型弦支穹顶结构作为研究对象，采用大型通用有限元分析软件ANSYS，对结构在强烈地震作用下的动力稳定性进行计算分析。主要内容如下：1、首先对弦支穹顶结构的自振特性进行分析，并与相应单层网壳进行对比。考虑了多种结构参数对结构自振特性的影响，其中包括：支座条件、矢跨比、拉索布置层数、初始预应力、结构荷载等参数，总结了弦支穹顶结构自振特性规律。2、分别计算了结构在一维和多维地震作用下的动力稳定性，并进行对比分析。总结三向地震作用下弦支穹顶结构动力失稳特点。结果表明：水平与竖向地震作用下结构的响应显著不同：三向地震作用下结构的动力响应均高于单向地震作用下结构的动力响应，此时得到的动力稳定临界荷载与单向地震作用下的结果相比显著降低。强烈地震作用下结构的响应不是完全均匀对称的。由于下部索杆体系提高了结构布索区域的刚度，结构最终破坏时布索区域没有明显的局部凹陷，导致结构破坏的凹陷通常发生在刚度突变的区域和未布索的区域。3、初步探讨了强烈地震作用下弦支穹顶的两种破坏形态：动力失稳和强度破坏。矢跨比决定了结构的两种破坏形态。地震作用下，矢跨比较大的弦支穹顶结构动力失稳破坏具有明显的突然性；小矢跨比(结构扁平)弦支穹顶结构在强烈地震作用下结构的动力稳定问题已不突出，应主要从强度方面考虑。4、系统分析各结构参数对弦支穹顶结构动力稳定性的影响。考虑的参数包括：支座条件的影响；矢跨比的影响；初始缺陷的影响；杆件截面的影响；布索层数的影响；拉索预应力值的影响；不同地震记录输入的影响。本文结论可为弦支穹顶结构的工程应用和后续的理论分析提供有价值的参考。更多还原

【Abstract】 As a new type of spatial structural form, and by using the concept of Tensegrity structure, the suspendome structure integrates the single layer reticulated shell structure and the cable-dome structure. It is a new structure with vital energies which combines both benefits of the single layer shell and cable dome and can cover greater space properly and economically. Taking suspendomes with span of 50m as examples and by utilizing the software ANSYS, dynamic stability behavior of some proto-type suspendomes under severe earthquake is discussed. The main contents in this paper are as follows:1. Analysis on the free-vibration behavior is performed firstly, and a comparison between suspendome and the corresponding single layer shell is executed. Parametric analysis on free-vibration behavior is proceeded. The parameters in considering are: boundary conditions, rise-to-span ratios, prestress value of the cables, the number of the cable rings, structural loads. Some regular conclusions are drawn.2. Comparative analysis on dynamic stability of suspendome structure under single-dimensional and multi-dimensional earthquake excitations is carried out. The characteristic of dynamic stability of suspendome under multi-dimensional earthquake is generalized. The results indicate that there are marked diversities in response of the structure under single-dimensional and multi-dimensional earthquakes. And the responses are not entirely symmetrical. As the cable-bar system strengthen the structural rigidity, when the structure fail to work there is no remarkable sag in areas with cable-bar system. The sags which result in unstability often occur in the areas without cable-bar system and the top of suspendome.3. Dynamic instability and strength failure, two damage patterns of the structure under severe earthquake which determined by rise-to-span ratios are discussed tentatively.4. A comprehensive numerical study on dynamic stability behavior of some proto-type suspendomes is carried out with the following primary parameters: single-dimensional and multi-dimensional earthquakes, three different boundary conditions, various geometric and structural parameters , such as rise-to-span ratios , prestress value of the cables and the number of the cable rings, member cross-sections and various earth quake records.Some valuable conclusions are achieved for practical design and further study on the suspendome in this paper.更多还原