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，以便更好地将损伤与细长钢筋混凝土（RC）桥柱的性能联系起来。要研究的具体建模参数是所谓的塑性铰链长度，这有利于与非弹性行为相关的设计和分析任务。该方法将采用基于力学的方法，从简单的计算工具到RC柱非弹性响应的高保真建模。将这些计算工具与具有精确局部测量的严格实验程序联系起来，将为验证和校准新的基于力学的模型提供必要的数据。该研究将产生新的校准/验证的塑性铰长度模型，该模型与地震荷载下RC桥柱的局部损伤具有更好的相关性和/或一致性。交付成果包括用于定义塑性铰链长度的新模型，该模型平衡了设计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。当前的抗震设计技术正朝着规定与明确的损伤水平相关的局部应变水平的方向发展。如果成功，该研究将为从业者和研究人员提供有价值的数值工具，用于在这种新兴的设计理念中评估/设计RC柱。该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各种柱尺寸。研究成果将存档在开放存取库中，供他人使用。为本科生和研究生提供教育资源，如虚拟结构测试实验室，以促进他们的学习。为K-12学生和工科新生准备了拓展活动。pi将利用REU的补充资金，专门针对代表性不足的学生提供夏季研究奖学金。

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.