An Uplift Friction Damper for Seismically Resilient Mass-Timber Buildings

该奖项将研究交叉层压木材（CLT）地震力抵抗系统（SFRS）的低损伤解决方案，该系统使用一种新型的上提摩擦阻尼器（UFD）设备，用于地震弹性大规模木材建筑。UFD装置将包括在高层CLT建筑中预期的自然摇摆墙行为，提供稳定的能量耗散，并表现出自定心特性。预计在设计水平地震后，使用这些装置的建筑物的结构修复将是最小的。虽然CLT已经成为一种振兴木材工业的建筑材料，但仍然缺乏能够与基于CLT的SFRS的自然运动学整体整合的CLT专用地震能量耗散装置。CLT墙板本身不提供任何可测量的地震能量耗散。作为大型10层CLT建筑样本的有效载荷，在圣地亚哥加州大学的自然灾害工程研究基础设施（NHERI）振动台上进行测试，作为NSF奖1636164的一部分，“合作研究：高层木结构建筑基于回弹的抗震设计方法，发言人说：“这项计划会对安装在CLT建筑物样本上的UFD装置进行一系列测试。这些测试将连接分析模型和数值模型，并收集真实边界和地震荷载条件下的高保真测试数据。校准后的模型将被纳入概率数值框架，以建立一个抗震高木结构建筑的设计方法，从而形成一个更加多样化和生态可持续的城市景观。该项目将提供当地小学外展活动，将本科少数民族和代表性不足的群体的参与纳入研究活动，并促进研究生课程的创新。 项目数据将在NSF支持的NHERI数据库（https：//www.example.com）中存档并公开提供。www.DesignSafe-CI.org该奖项有助于NSF在国家减少地震灾害计划（NEHRP）中的作用。该有效载荷项目的研究目标是：1）桥接基本力学UFD模型，将地震弹性CLT基SFRS的地震响应预测所需的分析和数值模型连接起来，2）通过具有现实边界条件和地震荷载的大规模测试，通过验证和校准来表征基本动态UFD行为，以及3）整合低损伤，在高层木结构建筑的抗震设计方法中，基于摩擦的阻尼系统替代方案。为了实现这些目标，收集的测试数据将提供一个关键的途径，以可靠地建立数值和分析模型，扩展振动台测试结果，以广泛的原型建筑。大量木材原型建筑系统的抗震性能将通过使用增量动态分析的倒塌风险评估来建立。这将为建立基于CLT的SFRSs的基于规范的抗震性能因素的长期目标迈出第一步。该奖项反映了NSF的法定使命，并被认为值得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来支持。

This award will investigate a low-damage solution for cross-laminated timber (CLT) seismic force-resisting systems (SFRSs) using a novel uplift friction damper (UFD) device for seismically resilient mass-timber buildings. The UFD device will embrace the natural rocking wall behavior that is expected in tall CLT buildings, provide stable energy dissipation, and exhibit self-centering characteristics. Structural repair of buildings with these devices is expected to be minimal after a design level earthquake. Although CLT has emerged as a construction material that has revitalized the timber industry, there exists a lack of CLT-specific seismic energy dissipation devices that can integrate holistically with the natural kinematics of CLT-based SFRSs. CLT wall panels themselves do not provide any measurable seismic energy dissipation. As a payload to the large-scale, ten-story CLT building specimen to be tested on the Natural Hazards Engineering Research Infrastructure (NHERI) shake table at the University of California, San Diego, as part of NSF award 1636164, “Collaborative Research: A Resilience-based Seismic Design Methodology for Tall Wood Buildings,” this project will conduct a series of tests with the UFD devices installed on the CLT building specimen. These tests will bridge analytical and numerical models with the high fidelity test data collected with realistic boundary and earthquake loading conditions. The calibrated models will be incorporated in a probabilistic numerical framework to establish a design methodology for seismically resilient tall wood buildings, leading to a more diverse and eco-sustainable urban landscape. This project will provide local elementary school outreach activities, integrate participation of undergraduate minorities and underrepresented groups into the research activities, and foster graduate level curriculum innovations. Project data will be archived and made available publicly in the NSF-supported NHERI Data Depot (https://www.DesignSafe-CI.org). This award contributes to NSF's role in the National Earthquake Hazards Reduction Program (NEHRP). The research objectives of this payload project are to: 1) bridge the fundamental mechanistic UFD models linking analytical and numerical models necessary for seismic response prediction of seismically resilient CLT-based SFRSs, 2) characterize the fundamental dynamic UFD behavior with validation and calibration through large-scale tests with realistic boundary conditions and earthquake loadings, and 3) integrate low-damage, friction-based damping system alternatives within a resilience-based seismic design methodology for tall wood buildings. To achieve these objectives, the test data collected will provide a critical pathway to reliably establish numerical and analytical models that extend the shake table test results to a broad range of archetype buildings. The seismic performance of mass-timber archetype building systems will be established through collapse risk assessment using incremental dynamic analyses. This will provide a first step in the longer term goal of establishing code-based seismic performance factors for CLT-based SFRSs.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.