空间桁架大型临时看台风荷载分析方法

发布时间：2019-01-14 07:22

【摘要】：风荷载是大型临时看台最主要的水平荷载之一，可能会使大型临时看台存在整体倾覆的风险。加之临时看台周围布置一些广告牌等临时非结构围护设施，使看台结构受风面积增大，大大增加了临时看台结构上的风荷载。同时由于其与基础连接强度较弱，，在较强风力作用下极易发生倾覆。与永久看台结构相比较，临时看台结构的使用寿命较短，且目前为止国内并未发布统一的临时结构抗风设计相关规范，对临时看台设计时风荷载的取值方法还未见表述。因此，对特定的临时结构，需要进行单独分析以确定该结构上的风荷载。本文围绕大型临时看台结构风荷载的数值模拟、风荷载确定方法及其在软件中的应用展开了较为详尽的研究。主要研究内容如下：首先，对描述风场的各物理参数进行介绍，利用风压系数定义了临时看台上作用的风荷载，并对风场流经大型临时看台时流场绕流特性进行了研究。然后，通过数值模拟研究手段确定风对空间桁架临时看台产生的荷载作用，主要对临时看台周围有遮挡物、无遮挡物以及临时看台结构广告牌设施的表面平均风荷载分布特性进行了建模和仿真，分析得到不同工况下临时看台各受风面积表面的平均风压分布特性。并对数值模拟结果进行分析，提出了不同工况下可直接用于临时看台设计使用的压力系数。最后，确定了大型临时看台的风荷载施加方法，通过编程实现对大型临时看台结构风荷载的加载，使其可直接应用与工程实际。然后以0o风向角下临时看台无遮挡工况的风荷载模拟结果作为加载荷载，通过有限元分析得到风荷载作用下的大型临时看台结构的各个板面、空间桁架的应力、位移分布。
[Abstract]:Wind load is one of the most important horizontal loads in large temporary stands, which may result in the risk of overturning large temporary stands. In addition, temporary unstructured enclosure facilities such as billboards are arranged around the temporary stands, which increases the wind-affected area of the stands and greatly increases the wind load on the temporary stands. At the same time, because of its weak connection with the foundation, it is easy to overturn under the strong wind force. Compared with the permanent stand structure, the service life of the temporary stand structure is shorter, and up to now, there is no uniform code for the wind resistance design of the temporary structure in China, and the method of choosing the wind load in the design of the temporary stand has not been described. Therefore, for a particular temporary structure, a separate analysis is needed to determine the wind load on the structure. In this paper, the numerical simulation of wind load of large temporary stands structure, the method of wind load determination and its application in software are studied in detail. The main research contents are as follows: firstly, the physical parameters describing the wind field are introduced, the wind load acting on the temporary stands is defined by using the wind pressure coefficient, and the characteristics of the flow field around the wind field when the wind field flows through the large temporary stands are studied. Then, by means of numerical simulation, the wind load on the temporary stands of space truss is determined, mainly for the temporary stands around the temporary stands. The distribution characteristics of average wind load on the surface of billboard facilities with no shelter and temporary stands structure are modeled and simulated. The average wind pressure distribution characteristics of the surface of temporary stands under different conditions are obtained. The numerical simulation results are analyzed and the pressure coefficients which can be directly used in temporary stands design under different working conditions are proposed. Finally, the method of imposing wind load on large temporary stands is determined, and the loading of wind loads on large temporary stands structures is realized by programming, so that it can be directly applied to engineering practice. Then, the simulation results of wind load under the unshielded condition of temporary stands at 0o wind direction angle are taken as the load loads, and the stress and displacement distributions of large temporary stands structures under wind loads are obtained by finite element analysis.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU312.1

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