Investigation of Discrepancies in Laboratory Wind Loading Modeling and Development of Standardized Wind Tunnel Testing Protocol for Low Buildings

2005年的卡特里娜飓风和威尔玛飓风以及最近的其他主要飓风和强风事件严酷地提醒人们，这些灾害的影响可能造成灾难性后果。 目前正在进行的关于需要采取社会行动以减少因风灾造成的生命和财产损失的全国性辩论导致了国家减少风暴影响方案的建立和方案实施计划的制定。这些努力的结果是确定了基础研究和应用研究的任务和子任务，以及完成计划目标所需的研究实施活动。这些活动的重要成果之一是为现有建筑物和其他结构的抗风设计以及现有基础设施的改造制定可靠的标准和规范。这些准则的改进需要分析工具的进步和高保真风和风载荷数据库的利用。研究解决了风载荷数据、空气动力学数据库等的质量/可靠性问题，用于低矮建筑物的抗风设计。概述的努力建立在这一领域的最新成就，从NIST/TTU合作协议的框架内进行的研究活动的结果？风暴减缓倡议，以及NIST协调的低建筑物风荷载实验室间比较研究。实验研究是科罗拉多州立大学（CSU）目前正在进行的研究活动的延伸。利用新获得的1024个通道的压力在计划的风洞试验将允许采集，分析包括在开发的数据库中的广泛的风荷载datasets. The研究的具体目标是：（1）识别可变的来源，风荷载在不同的风工程实验室获得在过去的实验室测试和它们对设计风荷载的影响;（2）制定标准化测试协议，以减少实验室风荷载的变化;（3）为国家抗风设计空气动力学数据库作出贡献。 为实现这些目标，研究工作分为以下五个方面：（1）在第一阶段试验期间，在参与风洞实验室中对风荷载的离散性进行研究;（2）评估风荷载的可变性对低矮建筑物风效应的影响;（3）在参与实验室中开展第二阶段风洞研究;（4）分析参与计划的实验所提供的第二阶段风荷载;及（5）制订标准化风洞程序拟稿，以确定低矮建筑物的风荷载。所描述的工作包括比较研究，在CSU和参与的风工程实验室进行风洞试验，交换技术信息（包括两个研讨会），与参与的实验室和NIST的研究团队合作，以及联合开发测试方法和低建筑物风荷载隧道模拟的标准化协议。上述活动的更广泛影响包括制定和验证标准化工具，以制定可靠的风标准和规范，从而设计新的和改造现有的建筑物（和其他结构），大大提高抗风能力。该研究的智力价值在于识别现有测试方法、经验模型和其他因素及其对设计风荷载（和相关误差/近似值）的影响中的不一致性和缺陷，并根据对物理现象的更好理解和先进实验和分析/数值工具的利用，制定对这些限制的补救措施。

The 2005 experience with Hurricane Katrina and Wilma, as well as other major recent hurricanes and strong wind events, is a grim reminder of potentially catastrophic effects of impacts of such hazards. Ongoing national debate on societal action needed to reduce loss of life and property damage due to wind hazards led to establishment of the National Windstorm Impact Reduction Program and development of the program implementation plan. These efforts resulted in identification of tasks and subtasks for fundamental and applied research, and the research implementation activities needed to accomplish the program goals. One of the critical outcomes of such activities is development of reliable standards and codes for wind-resistant design of existing buildings and other structures, and retrofit of the existing infrastructure. Improvements in such guidelines require advancements in analytical tools and utilization of high fidelity wind and wind loading databases.The research addresses the issue of quality/reliability of the wind loading data, aerodynamic databases, etc., for wind-resistant design of low buildings. The outlined effort builds on recent accomplishments in this area, resulting from research activities carried out within the framework of the NIST/TTU Cooperative Agreement ? Windstorm Mitigation Initiative, and the inter-laboratory comparative study of wind loading on low buildings coordinated by NIST. The experimental investigations are an extension of current ongoing research activities at Colorado State University (CSU). Utilization of the newly acquired 1024-channel pressure in the planned wind tunnel testing will allow for acquisition, analysis of inclusion in the developed database of extensive wind loading datasets.Specific objectives of the research are: (1) Identification of sources of variability in wind loading acquired at various wind engineering laboratories during past laboratory testing and their effects on design wind loading; (2) Development of standardized testing protocol to reduce variability in laboratory wind loading; and (3) Contribution to national aerodynamic database for wind-resistant design. The research effort to address these objectives is divided into the following five tasks: (1) Investigation of Discrepancies in Wind Loading Obtained during Phase I Testing at Participating Wind Tunnel Laboratories; (2) Assessment of Impact of Variability in Wind Loading on Wind Effects on Low Buildings; (3) Development of Phase II Wind Tunnel Studies at Participating Laboratories; (4) Analysis of Phase II Wind Loading Provided by Participating Laboratories; and (5) Formulation of Draft Standardized Wind Tunnel Procedures for Determining Wind Loading on Low Buildings. Delineated work comprises of comparatives studies, wind tunnel testing at CSU and at participating wind engineering laboratories, exchange of technical information (including two workshops), collaboration with participating laboratories and a research team at NIST, and joint development of testing methodology and standardized protocol for tunnel simulation of wind loading on low buildings. The broader impact of the above activities includes formulation and validation of standardized tools for development of reliable wind provisions of standards and codes, leading to design of new and retrofit of existing buildings (and other structures) of significantly improved wind resistance. The intellectual merit in the study is the identification of inconsistencies and deficiencies in the existing testing methodologies, empirical models, and other factors and their effects on design wind loads (and associated errors/approximations), and the development of remedies to these limitations, based on improved understanding of physical phenomena and utilization of advanced experimental and analytical/numerical tools.