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严重和昂贵的破坏。由此造成的内部雨水破坏和建筑功能的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。过去对大风事件后损坏的研究已经认识到，超过80%的玻璃破碎是由风吹来的碎片（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。适当的经济有效的解决方案始于对这一脆弱性的全面理解。然而，密集建筑周围高度湍流的城市风场极大地复杂化了风载碎屑运输和冲击的准确建模和预测。该项目将通过以下三种方式对碎片冲击集群城市建筑的潜在物理过程进行建模：1)在美国国家科学基金会（nsf）支持的自然灾害工程研究基础设施（NHERI）的佛罗里达大学边界层风洞中进行新的风洞测试项目；2)数据驱动的计算机模拟方法；3)基于碎片起源、飞行和冲击的物理模型。结果将是一个新的碎片破坏脆弱性评估平台，使风险一致的努力能够减少城市建筑围护结构的风力破坏。在研究的同时，将开发一种交互式增强现实工具，以可视化建筑物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，该项目将让来自代表性不足群体的高中生接触工程学，并鼓励他们走上STEM职业道路。本项目产生的数据将存档并在NHERI数据仓库（https://www.DesignSafe-ci.org）中公开提供。该研究项目将通过对复杂的城市流特征和建筑群周围碎片飞行轨迹的明确建模，推进对城市风中碎片运输的潜在物理特性的理解和建模。这将直接解决目前在城市风载碎片危害机制建模中存在的知识差距。新的风洞实验技术将使项目团队能够捕获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。通过主动学习，将风洞实验和数据驱动建模结合起来，有效地预测没有风洞数据的通用建筑群的风场。将开发一个概率不确定性量化程序，通过严格传播碎片来源、城市风场、碎片轨迹和撞击模型的不确定性，来评估风载碎片损害风险。该项目的成果将有助于评估和改善城市建筑群的飓风恢复力，这是社区恢复力规划中存在的重大研究空白。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

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.