Collaborative Research: Damage Compliant Inelastic Design Parameters for Performance-Based-Seismic-Design of Slender RC Columns

该奖项的研究目标是开发和校准非弹性建模参数，以更好地将损伤与细长钢筋混凝土(RC)桥柱的性能关联起来。要研究的具体建模参数是所谓的塑性铰长度，它便于与非弹性行为相关的设计和分析任务。该方法将采用一种基于力学的方法，并从简单的计算工具发展到对RC柱的非弹性反应进行高保真建模。将这些计算工具与具有精确本地化测量的严格实验程序相联系，将为验证和校准新的基于力学的模型提供必要的数据。这项研究将导致新校准/验证的塑性铰链长度模型，该模型具有更好的相关性和/或符合在地震荷载下在RC桥柱中发展的局部损伤。交付成果包括定义塑料铰链长度的新模型，这些模型平衡了设计的便利性和力学分析的严谨性，同时提供了与损伤相关的能力的准确性。目前抗震设计的技术水平正朝着规定与明确定义的破坏水平相关的局部应变水平的方向发展。如果成功，这项研究将为从业者和研究人员提供宝贵的数值工具，用于在这种新兴的设计理念下评估/设计RC柱。这项研究将为基于性能的设计中的非弹性建模创建一个统一的框架，该框架将适用于桥梁和建筑结构中的一系列柱尺寸。研究成果将存档在开放获取的储存库中，供其他人使用。将为本科生和研究生创建虚拟结构测试实验室等教育资源，以促进他们的学习。计划为K-12学生和工程专业一年级学生开展外展活动。PIS将利用REU的补充资金利用该项目，专门为代表人数不足的学生提供暑期研究奖学金。

The research objective of this award is to develop and calibrate inelastic modeling parameters that better correlate damage to performance of slender reinforced concrete (RC) bridge columns. The specific modeling parameter to be investigated is the so-called plastic hinge length, which facilitates design and analysis tasks related to inelastic behavior. The approach will employ a mechanics-based methodology and progress from simple computational tools to high-fidelity modeling of the inelastic response of RC columns. Linking of these computational tools to a rigorous experimental program with accurate localized measurements will provide the necessary data to validate and calibrate the new mechanics-based models. The research will result in newly calibrated/validated plastic hinge length models with improved correlation and/or compliance with local damage that develop in RC bridge columns during seismic loads. Deliverables include new models for defining plastic hinge length that balance the design convenience and the analytical rigor of mechanics, while providing accuracy in their ability to relate to damage. Current state of the art in seismic design is moving towards prescribing localized strain levels that correlate to a well-defined damage level. If successful, the research will provide valuable numerical tools for practitioners and researchers to use in the assessment/design of RC columns within this emerging design philosophy. The research will create a unifying framework for inelastic modeling in performance based design, which will be applicable to a range of column sizes in bridge and building structures. Research results will be archived in open-access repositories for utilization by others. Educational resources for undergraduate and graduate students such as a virtual structural testing laboratory will be created to facilitate their learning. Outreach activities are planned for K-12 students and freshmen engineering students. The PIs will leverage the project with REU supplementary funding for summer research fellowships exclusively targeted at underrepresented students.