台风作用下悬挂网壳风荷载特性的数值模拟

发布时间：2018-06-20 11:51

本文选题：悬挂网壳 + 台风　；参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：大跨度拱支索拉悬挂网壳造型新颖、结构复杂,网壳完全悬空设计使得其对风荷载非常敏感。目前国内外对大跨度屋盖的抗风研究,大都针对一般网架、封闭式网壳及悬挑结构这几种结构,而针对这种完全悬挂网壳结构的风压分布情况研究还很少。台风是一种频发的自然灾害,尤其是沿海城市区域其所造成的损失为所有自然灾害之首。拱支索拉组合网壳结构在强风袭击时可能导致严重的风致损坏,不同的风向角、风攻角等因素的改变也可能对其产生较大影响。建筑结构荷载规范中目前还没有针对完全悬挂网壳结构风荷载的相关条文,参考类似的结构又不能准确描述悬挂网壳实际的风荷载情况。所以,对在台风工况下的悬挂网壳结构表面风荷载分布情况及外界各种因素对其产生的影响研究非常必要,能够对以后此类结构的设计阶段提供更加具体的依据,从而使结构安全系数更高。基于台风的性质,总结目前大跨度空间结构抗风特性的研究现状和结构风荷载的几种研究手段及优缺点,阐述了风工程数值模拟的理论基础及方法。基于这些理论和方法,依靠流体力学分析软件Fluent,选用对钝体绕流有较好效果的SST k-ω湍流物理模型,对某复杂大型比基尼广场悬挂屋盖进行了在台风作用下的风荷载分布特性研究,研究了悬挂网壳在不同来流风向角和不同风攻角作用时网壳上下表面的风压变化情况,分析给出每种工况下网壳风压系数分布图及结构的风荷载敏感区域。结果表明,风向角、风攻角的变化对非规则悬挂屋盖表面的风压影响很大。分析了该悬挂网壳在田浦湍流强度、石沅湍流强度及常规湍流强度下悬挂网壳的风荷载分布情况,并将三种湍流强度的模拟结果作对比,得到三种湍流强度均能较好的模拟台风风场。在分析悬挂网壳在不同来流工况时结构表面风压分布规律基础上,还对此悬挂网壳周边环境因素的变化对其表面风压分布情况的影响进行了研究。同样的软件参数设置,对不同环境因素工况下网壳表面的风压分布情况进行了研究。研究了悬挂网壳在围护结构、所处地势高度变化、周边建筑物干扰及自身拱梁的影响四种因素影响时,结构表面的风压分布情况,将不同工况下模拟得出的结果作对比。研究表明,悬挂网壳在有围护结构时表面风荷载分布发生了较大的改变,并且不同的风向角下围护结构对网壳的影响效果不同,在考虑周边建筑及拱梁时其表面风压系数值的大小会有一定的减弱,随着悬挂网壳所处平台高度的增加,网壳表面风荷载也相应增大。
[Abstract]:The large span arch supported cable suspension reticulated shell is novel and complex, and the design of the reticulated shell is very sensitive to the wind load. At present, the wind resistance research of the large span roof is mostly aimed at the structure of the general network frame, the closed latticed shell and the cantilever structure, and the wind pressure distribution of the completely suspended latticed shell structure is made by the needle. The typhoon is a frequent natural disaster, especially in the coastal city area. The loss of the coastal urban area is the first of all natural disasters. The structure of the arch branch cable combination reticulated shell may cause severe wind damage during the strong wind attack, and the changes of the factors such as different wind direction angle and wind attack angle may also have great influence on it. There are no relevant provisions on the wind load of the fully suspended reticulated shell structure in the structural load code, which can not describe the actual wind load on the suspended latticed shell with reference to similar structures. Therefore, the distribution of wind load on the surface of the suspended latticed shell structure under the typhoon condition and the influence of various external factors on it are not studied. It is often necessary to provide more specific basis for the design stage of this kind of structure in the future, so as to make the structural safety factor higher. Based on the nature of the typhoon, this paper summarizes the current research status of the wind resistance characteristics of the large span space structure and the advantages and disadvantages of the structure wind load, and expounds the theoretical basis and the square of the numerical simulation of the wind engineering. Based on these theories and methods, based on the fluid mechanics analysis software Fluent, the SST k- Omega turbulent physical model which has a good effect on the flow around the blunt body is selected. The wind load distribution characteristics of the suspended roof of a complex large bikini square under the action of typhoon are studied, and the wind direction angle and the different wind attack of the suspended reticulated shell are studied. The wind pressure coefficient distribution of the reticulated shell and the wind load sensitive area under each working condition are given. The results show that the wind direction angle and the wind attack angle have great influence on the wind pressure of the irregular suspended roof. The wind load distribution of the suspended latticed shell under the conventional turbulence intensity is compared, and the simulation results of the three kinds of turbulence intensity are compared, and three kinds of turbulence intensity can be obtained to simulate the typhoon wind field. The influence of the distribution of the surface wind pressure on the surface wind pressure is studied. The same software parameters are set up to study the wind pressure distribution on the surface of the reticulated shell under different environmental conditions. The effect of four factors on the suspension reticulated shell in the enclosure structure, the height change, the disturbance of the surrounding buildings and the influence of its own arch are studied. The distribution of wind pressure on the surface of the structure is compared with the simulated results under different working conditions. The study shows that the surface wind load distribution of the suspended reticulated shell has been greatly changed, and the effect of the different wind direction angles on the reticulated shell is different, and the surface wind pressure values of the surrounding buildings and the arch beams are considered. The size of the reticulated shell will increase as the height of the platform increases.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU399;TU312.1

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