Collaborative Research: Converging Design Methodology: Multi-objective Optimization of Resilient Structural Spines

新西兰、智利和日本的震后重建工作正在推动开发新的、低损害的侧向力抵抗系统，以最大限度地减少社会干扰和财产损失。这些努力，再加上突出美国城市地震风险的地震情景，促使美国机构通过定义地震后重新入住率和功能恢复指标方面的绩效目标，专注于提高城市对未来极端事件的韧性。与此同时，非营利组织正在推动使用更可持续的建筑材料和建筑做法。该项目将在结构工程中创造一种新的设计模式，采用多目标优化，最大限度地实现地震后的功能恢复，同时将可持续的建筑做法纳入设计过程。新的设计范式将应用于弹性体量木结构体系的设计和施工。大量木结构的新颖性和有限的规范和标准使其在开拓创新的结构系统和新的设计范例方面具有独特的地位，例如纳入多目标优化。在这个项目中开发的独特的设计范例被称为“融合设计”，因为该方法将能够更好地融合相互竞争的生命安全、地震后功能恢复和环境可持续发展目标。这项研究将得到一个外展项目的补充，该项目包括培训下一代行业和学术领袖，并促进学术界、行业、建筑规范官员和政府机构之间更多的合作伙伴关系。此外，这项研究将通过院校研究和本科生推广经验计划以及与NSF资助的本科生研究经验网站的合作，带来几个本科生在STEM的经验。该项目将支持国家科学基金会(NSF)在国家减少地震灾害计划中的作用。该项目的目标是将基于功能的设计和多目标优化集成到一个单一的融合设计范例中，以支持横向抗力系统的弹性、可持续的抗震解决方案。该项目将整合实验室和数值工作的现有数据和新数据，以(1)定义功能恢复和可持续性指标，包括不确定性的量化，以用于使用大量木材脊柱解决方案的创新侧向力抵抗系统的设计；(2)创建和实施考虑弹性和可持续性目标的多目标优化收敛地震设计方法；(3)开发优化的地震侧向力抵抗系统，其性能通过NSF支持的自然灾害工程研究基础设施(NHERI)室外振动台(UCSD)的六层全尺寸建筑测试程序进行验证。六层高的样品重复使用了现有的十层振动台样品，该样品将于2021/2022年在加州大学圣地亚哥分校的振动台上进行测试。一系列专家访谈和参与性研讨会将支持弹性指标的定义，包括实现功能的时间和可持续性指标(例如，体现碳)，以实现研究目标。将创建用于工业和高等教育的教育模块。一个行业工作组将促进学术界、产业界和政府机构之间加强合作和促进创新。该项目将带来新的抗震设计可能性，并基于数十年的抗震设计研究、支持设计优化的高性能计算进展以及包括可持续性目标在内的功能恢复建模，促进对大型木结构功能和可持续性的了解。项目数据将被存档并在国家科学基金会数据仓库中公开提供(https://www.designsafe-ci.org).This奖反映了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。

Post-earthquake reconstruction efforts in New Zealand, Chile, and Japan are motivating the development of novel, low damage lateral force resisting systems to minimize social disruptions and property damage. These efforts, combined with earthquake scenarios highlighting seismic risks to cities in the United States, have led U.S. agencies to focus on increasing urban resilience against future extreme events by defining performance goals in terms of post-earthquake re-occupancy and functional recovery metrics. In parallel, non-profit organizations are driving the use of more sustainable building materials and construction practices. This project will create a new design paradigm within structural engineering that employs multi-objective optimization to maximize post-earthquake functional recovery while integrating sustainable building practices into the design process. The new design paradigm will be applied to the design and construction of resilient mass timber structural systems. The novelty of mass timber construction and limited availability of codes and standards make it uniquely positioned to pioneer innovative structural systems and new design paradigms, such as incorporating multi-objective optimization. The unique design paradigm developed in this project is called "converging design," as the methodology will be better able to converge across competing life-safety, post-earthquake functional recovery, and environmental sustainability objectives. The research will be complemented by an outreach program that includes training of the next generation of industry and academic leaders and fosters increased partnerships among academia, industry, building code officials, and government agencies. In addition, the research will lead to several undergraduate student experiences in STEM through an institutional Research and Extension Experiences for Undergraduate Student program and collaborations with NSF-funded Research Experiences for Undergraduates sites. This project will support the National Science Foundation (NSF) role in the National Earthquake Hazards Reduction Program. The goal of this project is to integrate functionality-based design and multi-objective optimization into a single converging design paradigm that will support resilient, sustainable seismic solutions for lateral force resisting systems. The project will integrate existing and new data from laboratory and numerical work to (1) define functional recovery and sustainability metrics, including quantification of uncertainty, for the design of innovative lateral force resisting systems employing mass timber spine solutions; (2) create and implement a multi-objective optimization converging seismic design methodology that considers resiliency and sustainability goals; and (3) develop optimized seismic lateral force resisting systems, whose performance is validated through a six-story full-scale building test program at the NSF-supported Natural Hazards Engineering Research Infrastructure (NHERI) outdoor shake table at the University of California, San Diego (UCSD). The six-story specimen re-uses an existing ten-story shake table specimen that will be tested on the UCSD shake table in 2021/2022. A series of expert elicitation interviews and participatory workshops will support the definition of resiliency metrics, including time to functionality and sustainability metrics (e.g., embodied carbon) to meet the goal of the research. Educational modules for industry and higher education will be created. An industry working group will promote increased collaboration and foster innovation among academia, industry, and government agencies. This project will lead to new seismic design possibilities and advance knowledge of the functionality and sustainability of mass timber structures based on decades of research in seismic design, advances in high-performance computing that support optimization in design, and functional-recovery modeling, including sustainability goals. Project data will be archived and made publicly available in the 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.