Impact of Falling Debris in Structural Collapse Progression

该奖项将提高建筑物的安全性和弹性，使工程界能够更好地了解建筑物因各种原因而倒塌的过程，如地震、风、碰撞、劣质设计和施工错误。结构倒塌可能是由于整个建筑构件的局部破坏造成的。虽然潜在的局部破坏几乎不可能消除，但由于结构构件坠落造成的影响，倒塌的进展可能是有限的。然而，目前的工程分析方法在预测坠落碎片的速度和形状、撞击时的能量损失以及结构元件对碎片撞击的响应方面缺乏能力。因此，没有合适的方法来预测坠落的碎片是否会导致坍塌的进展。了解坠落的碎片如何导致进一步倒塌，可以带来阻止建筑物倒塌和防止死亡的技术。在本奖项中开发的改进的分析工具将通过未来改进的代码规定和详细的标准来促进国家繁荣和福利，这些标准将为结构崩溃提供额外的抵抗。此外，该项目将向不同的高中生提供外展服务，并教育大学本科生和研究生。该奖项对国家科学基金会(NSF)在国家减少地震灾害计划(NEHRP)和国家减少风暴影响计划(NWIRP)中的作用做出了贡献。该项目的目标是通过实验和分析研究，对坠落的结构碎片负荷有一个基本的了解。将开发改进的分析工具(建模方法和简化分析)，以改进坍塌预测，并导致未来的设计，可以有效地限制坍塌进程。这项研究将产生关键的实验数据和分析模型，以回答三个基本的冲击问题：(1)坠落碎片的速度、形状和条件，(2)能量损失和如何分析冲击，以及(3)受冲击梁的动态响应(强度和延性)。该项目将通过(1)分析以前的坍塌试验来确定坠落碎片的速度、形状和条件，(2)通过实验落梁撞击试验来评估冲击和强度上的能量传递，以及(3)对子结构和原型建筑进行详细的有限元数值分析，以分析坠落碎片的影响并提供经过验证的建模方法，从而实现其目标。结果将用于开发详细和简化的分析工具，这些工具可以分析坠落的碎片，以预测坍塌进程。

This award will lead to improved safety and resiliency of buildings by enabling the engineering community to better understand the collapse process of buildings due to various causes, such as earthquakes, wind, collision, deterioration, poor design, and construction errors. Structural collapse can occur due to local failures that progress throughout the building’s members. While the potential local failure is nearly impossible to eliminate, the progression of collapse by the impact of falling structural members can be limited. However, current engineering analysis methods are lacking in the ability to predict the velocity and shape of the falling debris, the loss of energy on impact, and the response of the structural elements to the debris impact. Therefore, there is no suitable way to predict if the falling debris will cause a progression of collapse. Understanding how falling debris can lead to further collapse can lead to techniques to halt collapse in buildings and prevent fatalities. The improved analysis tools developed in this award will serve to advance national prosperity and welfare through future improved code provisions and detailing standards that will provide additional resistance to structural collapse. In addition, this project will provide outreach to diverse high school students and educate college undergraduate and graduate students. This award contributes to the National Science Foundation (NSF) role in the National Earthquake Hazards Reduction Program (NEHRP) and the National Windstorm Impact Reduction Program (NWIRP). The goal of this project is to achieve a fundamental understanding, through experimental and analytical studies, of falling structural debris loading. Improved analysis tools (modeling methods and simplified analysis) will be developed to improve collapse prediction and lead to future designs that can efficiently limit collapse progression. The research will generate critical experimental data and analytical models to provide answers to three fundamental impact questions: (1) velocity, shape, and condition of the falling debris, (2) amount of energy lost and how to analyze the impact, and (3) dynamic response (strength and ductility) of the impacted beam. The project will achieve its goal through (1) analysis of previous collapse tests to determine the velocity, shape, and condition of falling debris, (2) experimental drop beam impact tests to evaluate energy transfer on impact and strength, and (3) detailed finite element method numerical analysis of substructure and prototype buildings to analyze the effects of falling debris and provide validated modeling approaches. The results will be used to develop detailed and simplified analytical tools that can analyze falling debris for prediction of collapse progression. Data from this project will be archived in the NSF-supported Natural Hazards Engineering Research Infrastructure (NHERI) Data Depot (https://www.DesignSafe-ci.org).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.