CAREER: Mitigation of Seismic Risk to Critical Building Contents via Optimum Nonlinear 3D Isolation

这项教师早期职业发展（Career）资助将推进建筑抗震隔离解决方案的设计、分析和实施，克服现有限制，确保关键设施中关键任务设备的震后功能。为了公共福利和安全，应急中心和医院等基本设施必须在地震期间和地震后继续运作。地震隔离系统，如滚动隔离平台，是保护此类设施内单个组件或设备组的可行手段。然而，这些系统目前的位移能力有限，并且没有垂直激励的保护，这降低了它们在强烈的三方向地震引起的地板运动下的性能。该研究项目将开发一个多目标、风险知情的框架来优化三维隔震系统，推进使用该框架设计的被动三维隔震系统的数学建模，并通过实验验证在三方向地震载荷下的预测性能。这些新知识，再加上改进的设计工具，将使实践工程师更好地了解这些系统的行为，并采取创新策略来减轻对重要设备的损害，从而减少国家基本设施的脆弱性。该研究计划将融入旨在促进工程多样性的教育活动中，并通过低成本的教育振动台模块为K-12、本科生和研究生创造实践教育机会。项目数据将存档并在自然灾害工程研究基础设施数据库（https://www.DesignSafe-ci.org）中公开提供。本项目为国家科学基金和国家减少地震灾害计划提供资助。本研究的总体目标是通过更深入地了解其潜在物理特性来推进3D隔震策略，并优化、评估和验证其性能。本研究将回答以下基本问题：(a)如何在从频繁到罕见的各种强度的三向地震激励下可靠地确保基本设施及其内容的不间断运行，以及(b)如何通过创新材料和优化方法增强设备隔离系统固有的性能能力。该项目的具体任务旨在：(1)描述三维地震对关键建筑内容的危害，并为这些组件定义基于风险的性能目标；(2)发现并实现了由滚动摆轴承和准零刚度隔振器组成的具有响应适应性的被动三维隔振系统的最佳非线性恢复力和阻尼力；(3)通过实验验证这些防护系统的基于物理的数学模型，以便在设计中用于捕捉地震荷载下发生的复杂行为；(4)建立一个设计框架，以便将这一概念直接转化为工程实践。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。

This Faculty Early Career Development (CAREER) grant will advance the design, analysis, and implementation of seismic isolation solutions for buildings, overcoming existing limitations to ensure post-earthquake functionality of mission-critical equipment in essential facilities. Essential facilities, such as emergency response centers and hospitals, must remain operational during and after an earthquake for the public welfare and safety. Seismic isolation systems, such as rolling isolation platforms, are a viable means of protecting individual components or groups of equipment within such facilities. These systems, however, presently suffer from limited displacement capacity and no protection from vertical excitations, diminishing their performance under strong tri-directional earthquake-induced floor motions. This research project will develop a multi-objective, risk-informed framework to optimize 3D isolation systems, advance the mathematical modeling of passive 3D isolation systems designed using the framework, and experimentally verify the predicted performance under tri-directional seismic loading. This new knowledge, coupled with improved design tools, will allow practicing engineers to better understand the behavior of these systems and to pursue innovative strategies to mitigate damage to vital equipment, thus reducing the vulnerability of the nation's essential facilities. The research plan will be woven into educational activities aimed at promoting diversity in engineering and creating hands-on educational opportunities for K-12, undergraduate, and graduate students through a low-cost, educational shake table module. Project data will be archived and made publicly available in the Natural Hazards Engineering Research Infrastructure Data Depot (https://www.DesignSafe-ci.org). This project contributes to the National Science Foundation role the National Earthquake Hazards Reduction Program. The overarching objective of this research is to advance 3D seismic isolation strategies through a deeper understanding of their underlying physics and to optimize, evaluate, and validate their performance. This research will answer fundamental questions related to (a) how the uninterrupted operation of essential facilities and their contents can be reliably ensured under tri-directional earthquake excitations of various intensities from frequent to rare events, and (b) how the performance capacity inherent to equipment isolation systems can be augmented with innovative materials and optimization approaches. The specific tasks of the project are aimed at: (1) characterizing 3D seismic hazards to critical building contents and defining risk-based performance objectives for these components; (2) discovering and realizing optimum nonlinear restoring and damping forces for passive 3D isolation systems composed of rolling pendulum bearings and quasi-zero stiffness isolators that exhibit response-based adaptation; (3) experimentally validating physics-based mathematical models of these protective systems for use in design to capture the complex behavior that occurs under seismic loading; and (4) establishing a design framework to facilitate the direct transfer of this concept to engineering practice.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.