The effect of multidirectional high intensity winds on aerodynamic response of structures

多向强风对结构气动响应的影响

• 批准号: 371600-2010
• 负责人: Dragomirescu, Elena
• 金额: $ 1.46万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=461284
• 关键词: effect; multidirectional; intensity; winds; aerodynamic

The frequency of high intensity wind events, e.g., windstorms such as downbursts and tornadoes, has increased significantly. However, the Building Codes, currently in place in Canada do not have specific design guidelines for these types of extreme wind events. Therefore, an update of the design guidelines is required to integrate wind speed profiles, turbulence intensities and pressure fluctuations associated with these types of winds and to prescribe critical loads induced by downbursts and tornadoes on the structures located in windstorms prone regions. The current research proposal addresses these issues, focusing on three particular aspects: simulation of downburst multidirectional wind profile, investigation of wind loads induced by downbursts on two types of structures: low-rise buildings and cable-stayed bridges and finally proposing design code provisions that would integrate calibration of safety factors in regard to the effect of high intensity winds on the investigated structures. Analytical simulations of downburst winds will be performed as 3-D impinging jets with multi - dimensional wind profiles, of various inclinations characterized by a flux-dependent Reynolds number. Turbulence properties as quadrature and cospectrum for downburst winds will be determined wind velocity fluctuations will be calibrated against existent experimental measurements. Once established the downburst turbulence properties will serve for the flutter and buffeting analysis of long span bridges. A new formulation of aerodynamic flutter and buffeting forces on structures, which will include the downburst effect will be proposed for the use of Bridges Design Codes. The long-term objective of this research is to recommend a formulation of wind spectrum for downburst high intensity winds regions to be included in the new wind design guidelines. The pressure determined for downburst winds will also be applied to low-rise buildings with openings for determining the effect of breaches in the building envelop and for prescribing adjustment factors for corner and end zones of the buildings. The applicant's expertise is in the field of wind engineering, and she is an active member of the committee responsible for issuing the Japanese National Wind Design Guide.

高强度风事件的频率，例如，下击暴流和龙卷风等风暴已显著增加。然而，加拿大目前的建筑规范没有针对这些类型的极端风事件的具体设计指南。因此，需要更新设计指南，以整合与这些类型的风相关的风速剖面、湍流强度和压力波动，并规定由下击暴流和龙卷风对位于风暴易发区的结构物引起的临界载荷。目前的研究建议解决这些问题，集中在三个特定的方面：模拟下击暴流多方向风廓线，调查两种类型的结构：低层建筑物和斜拉桥，最后提出设计规范规定，将集成校准的安全系数方面的影响，高强度的风对调查结构的下击暴流引起的风荷载。下击暴流风的分析模拟将作为具有多维风廓线的三维冲击射流进行，其具有由通量依赖的雷诺数表征的各种倾角。下击暴流风的湍流特性，如正交和共谱，将被确定，风速波动将被校准对现有的实验测量。一旦建立，下击暴流湍流特性将用于大跨度桥梁的颤振和抖振分析。将提出一种新的结构气动颤振和抖振力公式，其中包括下击暴流效应，供桥梁设计规范使用。这项研究的长期目标是推荐一个下击暴流高强度风区的风谱公式，以纳入新的风力设计指南。为下击暴流确定的压力也将应用于有开口的低层建筑物，以确定建筑物围护结构中的破坏影响，并规定建筑物拐角和末端区域的调整系数。 申请人的专长是风力工程领域，她是负责发布日本国家风力设计指南的委员会的积极成员。