柱面网壳结构风敏感度及抗风设计方法研究

发布时间：2018-10-26 08:11

【摘要】：大跨度屋盖结构具有质量轻、柔性大、阻尼小的特点,风致振动效应显著,风荷载问题十分突出,是目前研究的热点领域。遗憾的是,由于大跨度屋盖结构自身独特的力学特性,与高层及高耸结构抗风设计相比,风致振动理论分析与工程实用设计方法并不完善,尚未形成一套成熟的理论、设计体系,在各国规范中更是鲜有提及。因此,如何为大跨度屋盖结构工程实践提供概念清晰、应用简单并能保证计算精度的抗风分析设计方法成为亟需解决的问题。目前一种可行的思路为:通过对结构进行系统参数分析,寻找风致振动响应特点及规律,并根据风致振动响应强度对不同结构进行风敏感度划分,进而归纳并提出相应简化计算方法指导工程实践。本文基于课题组之前提出的结构风敏感度概念,对原风敏感度理论进行探讨,对相关计算方法进行改进,并针对柱面网壳屋盖结构,建立风敏感度分级体系,提出相应的等效静风荷载实用确定方法。本文主要工作如下:(1)对风敏感度理论进行改进针对原风敏感度理论中的若干关键问题进行探讨,澄清相关概念,并对若干参数计算方法进行改进,推导了背景效应系数、耦合效应系数以及系统应变能等公式。(2)设计并实施柱面屋盖风洞试验设计并实施1/6、1/3、1/2矢跨比柱面屋盖刚性模型风洞测压试验,获得柱面屋盖表面在不同工况下的风荷载数据。(3)对柱面网壳结构进行系统风致振动分析根据《网壳结构技术规程》(JGJ61-2003)确定工程常用跨度b、矢跨比f/b、屋面质量、约束形式及钢管型号等参数,对柱面网壳结构进行系统风致振动分析,并将柱壳屋盖结构风致振动复杂的多参数问题,简化为结构振动模式和结构刚度两个简单参数。(4)建立柱面网壳结构风敏感度分级体系根据风致振动分析结果,对单层及双层柱面网壳结构进行风敏感度计算并统计分析,建立柱面网壳屋盖结构风敏感度分级体系。(5)建立基于风敏感度分级的等效静风荷载简化确定方法基于风敏感度理论提出的结构风致振动分析方法,对中等风敏感度单层及双层柱面网壳结构建立等效静风荷载简化确定方法,并给出可供工程实用的拟合公式。
[Abstract]:Long-span roof structure has the characteristics of light weight, large flexibility and small damping, the wind-induced vibration effect is obvious, and the wind load problem is very prominent, which is a hot research field at present. Unfortunately, due to the unique mechanical properties of long-span roof structures, compared with the wind-resistant design of high-rise and high-rise structures, the theoretical analysis of wind-induced vibration and practical engineering design methods are not perfect, and a set of mature theory has not yet been formed. Design system, in the national norms are rarely mentioned. Therefore, how to provide a clear concept for the practice of long-span roof structure, and how to apply the method of anti-wind analysis and design, which can guarantee the accuracy of calculation, has become an urgent problem to be solved. At present, a feasible way of thinking is to find out the characteristics and rules of wind-induced vibration response by analyzing the system parameters of the structure, and to divide the wind sensitivity of different structures according to the wind-induced vibration response intensity. Furthermore, the corresponding simplified calculation method is proposed to guide engineering practice. Based on the concept of structural wind sensitivity, this paper discusses the theory of original wind sensitivity, improves the related calculation method, and establishes a classification system of wind sensitivity for cylindrical reticulated shell roof structure. A practical method for determining equivalent static wind load is proposed. The main work of this paper is as follows: (1) to improve the wind sensitivity theory, to discuss some key problems in the original wind sensitivity theory, to clarify the related concepts, to improve the calculation method of some parameters, and to derive the background effect coefficient. Coupling effect coefficient and system strain energy. (2) designing and carrying out the wind tunnel test of cylindrical roof and carrying out the wind tunnel pressure measurement experiment of 1 / 6 / 1 / 3 / 3 / 1 / 2 ratio cylindrical roof rigid model. The wind load data of cylindrical roof surface under different working conditions are obtained. (3) the systematic wind-induced vibration analysis of cylindrical latticed shell structure is carried out. According to the Technical Specification for reticulated Shell structure (JGJ61-2003), the commonly used span b, sagittal span ratio f / b, are determined. The systematic wind-induced vibration of cylindrical latticed shell structure is analyzed by the parameters of roof quality, constraint form and steel pipe type, and the multi-parameter problem of wind-induced vibration of cylindrical shell roof structure is discussed. It is simplified to two simple parameters of structural vibration mode and structural stiffness. (4) the wind sensitivity classification system of cylindrical latticed shell structures is established. According to the results of wind-induced vibration analysis, the wind sensitivity of single-layer and double-layer latticed cylindrical shells is calculated and statistically analyzed. The wind sensitivity classification system of cylindrical reticulated roof structure is established. (5) the simplified equivalent static wind load determination method based on wind sensitivity classification is established. The wind induced vibration analysis method based on wind sensitivity theory is proposed. The simplified method of equivalent static wind load for single-layer and double-layer cylindrical latticed shell structures with medium wind sensitivity is established, and a practical fitting formula for engineering is given.
【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】：TU352.2;TU399

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