Collaborative Research: Modeling Hurricane-Induced Windborne Debris to Reduce Damage in Urban Communities

许多飓风后的调查报告说，城市地区建筑物的玻璃覆层和外墙受到了过度和代价高昂的破坏。由此造成的室内雨水破坏和建筑物功能长期丧失可能对城市社区内部和周围的社会经济系统产生重大不利影响。过去对强风事件后玻璃损坏的研究已经认识到，超过80%的玻璃破碎是由风吹碎片（如破碎的玻璃碎片和邻近建筑物的材料）造成的，而不是直接的风压加载玻璃。适当的具有成本效益的解决方案开始与全面了解这一脆弱性。然而，密集建筑群周围的高度湍流的城市风场大大增加了准确建模和预测风吹碎片的运输和影响的复杂性。该项目将通过以下几个方面的结合，模拟碎片撞击密集城市建筑物的基本物理过程：（1）在佛罗里达大学由国家科学基金会支助的自然灾害工程研究基础设施边界层风洞进行的一项新的风洞试验方案;（2）数据驱动的计算机模拟方法;（3）碎片起源、飞行和撞击的物理模型。其结果将是一个新的碎片损坏脆弱性评估平台，使人们能够作出风险一致的努力，减少风对城市建筑物外壳的损坏。在进行研究的同时，还将开发一个互动式增强现实工具，以显示建筑群周围的三维流动和碎片飞行轨迹。这将是一个暑期项目的核心，该项目将使来自代表性不足的群体的高中生接触工程，并鼓励STEM职业道路。 本项目生成的数据将在NHERI数据库（https：//www.example.com）中存档并公开提供。www.DesignSafe-ci.org这一研究项目将通过对复杂的城市流动特征和建筑群周围的碎片飞行轨迹进行明确建模，促进对城市风中碎片运输的基本物理学的理解和建模。这将直接解决目前在城市风吹碎片危害机制建模方面存在的知识空白。新的风洞实验技术将使项目小组能够捕捉三维城市风场和碎片轨迹，从而获得开发数据驱动的风场模型和系统验证复杂城市风的数值轨迹模型所需的首个此类数据。将通过主动学习开发风洞实验和数据驱动建模之间的新型集成，以有效预测风洞数据不可用的通用建筑群的风场。将制定一种概率不确定性量化程序，通过碎片源、城市风场、碎片轨迹和撞击模型的不确定性的严格传播，评估风载碎片造成损害的风险。该项目的成果将有助于评估和改善城市建筑群的飓风抵御能力，这是社区抵御能力规划中存在的一个重大研究空白。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Numerous post-hurricane investigations have reported excessive and costly damage to glass cladding and façades of buildings located in urban areas. The resulting interior rainwater damage and extended periods of loss in building functionality can have substantial adverse effects on the socio-economic systems within and surrounding urban communities. Past studies of damage after high wind events have recognized that more than 80% of glass breakage was caused by windborne debris (such as broken glass pieces and materials from neighboring buildings) rather than direct wind pressure loading the glass. Appropriate cost-effective solutions begin with a comprehensive understanding of this vulnerability. However, the highly turbulent urban wind field around densely clustered buildings significantly complicates the accurate modeling and prediction of windborne debris transport and impact. This project will model the underlying physical process of the debris impact on clustered urban buildings through a combination of 1) a novel wind tunnel test program at the NSF-supported Natural Hazards Engineering Research Infrastructure (NHERI) boundary layer wind tunnel at the University of Florida, 2) data-driven computer simulation approaches, and 3) physics-based models of debris origin, flight, and impact. The result will be a new debris damage vulnerability assessment platform that enables risk-consistent efforts to reduce wind damage to the urban building envelope. Concurrent with the research, an interactive augmented reality tool will be developed to visualize the three-dimensional flow around building clusters and debris flight trajectory. This will be the centerpiece of a summer program that exposes high school students from underrepresented groups to engineering and encourages STEM career paths. Data generated by this project will be archived and made publicly available in the NHERI Data Depot (https://www.DesignSafe-ci.org). This research project will advance the understanding and modeling of the underlying physics of debris transport in urban winds through explicit modeling of complex urban flow features and debris flight trajectories around building clusters. This will directly address the current knowledge gap present in modeling of urban windborne debris hazard mechanisms. New wind tunnel experimental techniques will enable the project team to capture three-dimensional urban wind fields and debris trajectories, resulting in first-of-its-kind data necessary for developing the data-driven wind field models and systematically validating numerical trajectory models for complex urban winds. A novel integration between the wind tunnel experiments and data-driven modeling will be developed through active learning to efficiently predict wind fields for generic building clusters where wind tunnel data is not available. A probabilistic uncertainty quantification procedure will be developed to evaluate windborne debris damage risk through rigorous propagation of uncertainties from debris sources, urban wind fields, debris trajectory, and impact models. The outcome of this project will enable assessment and improvement of hurricane resilience for urban building clusters, which is a significant research gap present in community resilience planning.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.