NEESR-CR: Collapse Simulation of Multi-Story Buildings through Hybrid Testing

这个奖项是一个结果的NSF 09-524计划征求“乔治E。小布朗地震工程模拟网络（NEES）研究（NEESR）”竞赛，包括斯坦福大学（牵头机构）、新罕布什尔州大学（副奖）、布法罗大学、纽约州立大学（副奖）和加州州立大学、萨克拉门托（副奖）。该项目将利用布法罗大学和伯克利加州大学的NEES设备场地。智力成果：抗震设计的主要目标是通过防止结构倒塌来保护生命安全。地面运动和结构对地面运动的响应的不确定性，以及经济上的限制，迫使人们接受小概率的倒塌。对这种小概率倒塌的评估需要有足够的信心来预测结构在倒塌过程中的反应。基于性能的地震工程的这一方面提出了重大的挑战，其中许多已经解决，并通过最近的研究部分解决。 但缺乏的是结构倒塌的实验数据和对分析组件和结构响应预测的信心，这需要通过使用实验研究结果进行仔细验证所提供的证据来培养。为了验证倒塌预测，并评估在组件测试中没有充分代表的现象，需要在结构水平上进行实验测试。振动台（地震模拟器）测试是一个很好的选择。然而，振动台试验倒塌是非常复杂的，非常昂贵的，并具有潜在的危险。混合测试正在成为一种有吸引力的替代方案，因为它可以提供整个结构的响应信息，而不必对所有结构进行物理测试。这使得混合测试成为一种通用且具有成本效益的测试方法。 这项研究将推进知识，以提高我们对结构接近崩溃时的反应的理解。具体目标是：（1）对倒塌混合模拟技术进行全面验证，其中包括各种倒塌模式（例如，棘轮行为-侧向变形在一个方向上逐渐累积）;（2）显著扩展分布式混合模拟中使用的子结构技术，以捕获时变边界条件的影响;（3）通过开发和合并自适应分析模型，显著扩展混合模拟的能力和可靠性;（4）了解和识别导致倒塌的棘轮行为的最重要的结构和地面运动参数;以及（5）开发和实施创新的教育、推广和技术转让机制，以传播有关崩溃的结构性反应的知识。这项研究的成功完成将改变多层建筑物倒塌模拟的方式，通过开发和验证混合测试程序，提供更有效和可靠的量化建筑物的倒塌潜力。主要的研究贡献将是新的物理测试方法和分析模拟方法的创建和集成，以更深入地了解导致结构系统倒塌的结构特性和地面运动特性。该研究整合了地震工程、结构动力学、系统控制和信息技术等领域的多学科知识。更广泛的影响：这项研究将提高可靠地估计倒塌概率的能力，这将有助于最大限度地减少人员伤亡，经济损失，并提高建筑物在地震事件中的弹性。创新的测试方法和数据将通过在NEES共享使用设备，软件和数据存储库中的实施以及通过出版物和演示文稿提供给地震工程界。一项综合外联计划包括与美国东西海岸的学校和本科院校建立伙伴关系，以及开展创新的外联活动，积极吸引代表性不足的学生参与工程和研究。该项目的数据将通过NEES数据库存档并向公众提供。

This award is an outcome of the NSF 09-524 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes Stanford University (lead institution), University of New Hampshire (subaward), University at Buffalo, The State University of New York, (subaward), and California State University, Sacramento (subaward). This project will utilize the NEES equipment sites at the University at Buffalo and the University of California at Berkeley. Intellectual Merit: The primary goal of earthquake resistant design is to protect life safety by preventing the collapse of the structure. Uncertainties in ground motion and in structural response to ground motion, together with economic constraints, impose the acceptance of a small probability of collapse. Assessment of this small probability of collapse requires the ability to predict, with sufficient confidence, the response of structures through collapse. This aspect of performance-based earthquake engineering poses major challenges, many of which have been addressed and partially solved through recent research. But what is lacking is experimental data of structures collapsing and confidence in analytical component and structure response predictions, which need to be fostered through evidence provided by careful validation using results from experimental studies. To validate collapse predictions and to evaluate phenomena that are not represented adequately in component tests, experimental tests at the structure level are needed. Shaking table (earthquake simulator) testing represents an excellent option. However, shaking table testing to collapse is very complex, very expensive, and potentially dangerous. Hybrid testing is becoming an attractive alternative because it can provide information on the response of the entire structure without having to physically test all the structure. This makes hybrid testing a versatile and cost-effective testing approach. This research will advance knowledge to improve our understanding of the response of structures as they approach collapse. The specific objectives are to: (1) conduct a comprehensive validation of hybrid simulation techniques to collapse, which includes tests with various collapse modes (e.g., ratchetting behavior-lateral deformations accumulating progressively in one direction); (2) significantly expand substructuring techniques used in distributed hybrid simulation to capture the effects of time-varying boundary conditions; (3) significantly expand the capabilities and reliability of hybrid simulation by developing and incorporating adaptive analytical models; (4) understand and identify the most important structural and ground motion parameters that cause ratchetting behavior leading to collapse; and (5) develop and implement innovative education, outreach, and technology transfer mechanisms to disseminate knowledge on structural responses to collapse. The successful completion of this study will transform the way in which collapse simulation of multi-story buildings is conducted through the development and validation of hybrid testing procedures that provide a more efficient and reliable quantification of the collapse potential of buildings. The main research contribution will be the creation and integration of new physical testing approaches and analytical simulation methods to develop a more in-depth understanding of the structural properties and ground motion characteristics that lead to collapse of structural systems. This research integrates multidisciplinary knowledge from the fields of earthquake engineering, structural dynamics, systems control, and information technology. Broader Impacts: This research will improve the ability to reliably estimate collapse probabilities, which will help minimize casualties, economic losses, and enhance the resiliency of buildings subjected to seismic events. Innovative testing methods and data will be made available to the earthquake engineering community through their implementation in the NEES shared use equipment, software, and data repository and through publications and presentations. An integrated outreach plan includes partnerships with schools and undergraduate institutions located in the east and west coasts of the United States, as well as innovative outreach activities to actively engage underrepresented students in engineering and research. Data from this project will be archived and made available to the public through the NEES data repository.