【作者】 常虹；

【导师】 武岳；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2014， 硕士

【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。更多还原

【Abstract】 The steel structure, especially the large-span space structure, which is widely used in large public buildings and large-scale stadiums, has serious wind-resistant design problems because of the features of the unique structural form and the random of wind loads. The sensitivity to fluctuating wind loads of a structure is a ground problem in the wind-resistant design theory. Based on the wind tunnel tests and dynamic analysis of cylindrical shells, my research aims to establish a method with physical connotative meaning to describe the wind sensitivity theoretically and contrive a simplified method for determining the equivalent static wind loads( ESWL).This thesis including:(1) improving of wind-sensitivity theoryBased on the conception of wind-sensitivity, some key issues of wind-sensitivity theory were discussed in this thesis, and the calculation algorithm of wind-sensitivity was improved. The coefficient of background response effect, coefficient of coupling effect for background and resonance respo nse and calculation formula of strain energy were defined and deduced theoretically.(2) designing and conducting of wind tunnel tests of cylindrical shel sA series of wind tunnel tests of cylindrical roofs with rigid models were designed and accomplished. The data of wind pressure on cylindrical roofs was obtained.(3) analysing of wind vibration of cylindrical roofs systematicallyThe influence of span, cross-sectional area, rise-span ratio and boundary conditions on the wind-sensitivity of cylindrical shells was studied systematically. The study indicates that, the wind-sensitivity of cylindrical shells is mainly affected by the stiffness and vibration mode, which are expressed by structural basic frequency, rise-span ratio and boundary conditions.(4) establishing classification system for the wind-sensitivity of cylindrical shel sBased on the results of wind- induced vibration response of cylindrical shells, the wind-sensitivity was calculated and analyzed. Then, classification system for the wind-sensitivity of cylindrical shel s was established.(5) establishing a simplified method for determining the equivalent static wind loadsBased on wind-sensitivity of cylindrical shells, a simplified method for determining the equivalent static wind loads was proposed and tested.更多还原