单层凯威特球面网壳稳定与抗连续性倒塌分析

发布时间：2019-03-06 08:39

【摘要】：单层凯威特球面网壳因其外形美观、受力合理、能够获得较大空间而被广泛的运用于会展中心、体育馆、航站楼等人群密集的公共建筑中,其一旦发生失稳或连续倒塌破坏,势必造成严重的人员伤亡、财产损失和社会影响。截至目前,全世界范围内发生了多起单层网壳在竖向雪荷载作用下失稳倒塌的事故。随着全球极端气候越来越严重,单层网壳遭遇暴雪荷载的可能性越来越高。由于单层凯威特球面网壳杆件及节点众多,当某些杆件或节点破坏后,该结构在竖向荷载(雪荷载)作用下还具有多大的抵抗失稳的能力,目前还没有文献对此进行相关的研究。与此同时随着地震的频繁发生,单层凯威特球面网壳在使用过程中可能会遭遇地震作用,在此情形下网壳结构能否继续承载而不发生连续倒塌破坏,这个问题也越来越受到人们的重视。综上可知,对单层凯威特球面网壳进行竖向荷载作用下的稳定分析与地震作用下的抗连续倒塌分析具有一定的理论意义和工程价值。本文通过有限元分析方法,借助ANSYS分析软件,结合工程中常用的单层凯威特球面网壳尺寸,分别以跨度(30m、40m、50m)、矢跨比(1/3、1/5和1/7)、支座约束数目为参数,运用拆除构件法对单层凯威特球面网壳进行了敏感度分析及竖向荷载作用下的稳定分析,最后计及缺陷影响分析了该网壳结构在地震作用下的抗连续倒塌性能。文章得出了各种工况下单层凯威特球面网壳在竖向荷载作用下的失稳临界荷载及地震作用下的抗连续倒塌极限承载力,并总结了各种参数对网壳失稳、抗连续倒塌性能的影响规律,可为实际工程设计提供参考。
[Abstract]:Single-layer Kewitt spherical latticed shell is widely used in public buildings such as convention and exhibition center, gymnasium, terminal building and so on because of its beautiful appearance and reasonable force, so it is widely used in public buildings such as convention and exhibition center, gymnasium, terminal building and so on. Once it becomes unstable or continuously collapses, it is destroyed. It is bound to cause serious casualties, property damage and social impact. Up to now, there have been many accidents of collapse of single-layer reticulated shells under vertical snow load all over the world. As the global extreme climate becomes more and more serious, single-layer reticulated shells are more and more likely to be subjected to blizzard loads. Because of the large number of members and joints of single-layer Kewitt spherical reticulated shell, when some members or joints are destroyed, how much of the structure can resist instability under vertical load (snow load). At present, there is no relevant research on this issue in the literature. At the same time, with the frequent occurrence of earthquakes, the single-layer Kewitt spherical latticed shell may be subjected to earthquake action in the process of use, in this case whether the reticulated shell structure can continue to carry the load without continuous collapse failure. People pay more and more attention to this problem. It can be seen that the stability analysis of single-layer Kewitt spherical latticed shell under vertical load and the analysis of anti-continuous collapse under earthquake have certain theoretical significance and engineering value. In this paper, by means of finite element method and ANSYS analysis software, combined with the size of single-layer Kewitt spherical reticulated shell commonly used in the engineering, the span (30m, 40m, 50m), the rise-to-span ratio (1x3, 1x5 and 1x7), respectively, are used in this paper. With the number of support constraints as the parameter, the sensitivity analysis and the stability analysis of the single-layer Kewitt spherical latticed shell under vertical load are carried out by using the method of removing members. Finally, the continuous collapse resistance of the latticed shell structure under earthquake is analyzed by taking into account the effect of defects. In this paper, the buckling critical load under vertical load and the ultimate bearing capacity of continuous collapse resistance of single-layer Kewitt spherical reticulated shell under various working conditions are obtained, and various parameters are summarized for the instability of reticulated shell. The influence law of anti-continuous collapse performance can provide reference for practical engineering design.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU399;TU312.3

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