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.
