This Broadening Participation Research Initiation Grant (BRIDGE) project develops a novel approach to assessing the reliability of experimental results using the real-time hybrid simulation technique for replicating actual structural responses during earthquakes. Real-time hybrid simulation is widely viewed as the most advanced tool for investigating the rate-dependent behaviors of structures. However, its application has been severely limited by the servo-hydraulic actuator delay induced tracking errors which accumulate and propagate in laboratory to study the behavior of large-scale structures under earthquakes. Building on previous research into the cumulative effect of actuator delay, this project will determine the effects of structural nonlinearity, substructure partitions, and variations in ground motion inputs and intensities. Data will be analyzed using numerical simulation of delay differential equations and correlation analysis between actuator delay and simulation accuracy. The project will result in the development of a probability-based energy error and tracking indicator which will enable the engineering community to assess the reliability of experimental results and to validate these results, especially when the actual structural responses under earthquakes are not available for an immediate comparison. The research will fill a significant knowledge gap in the earthquake engineering community by resolving a problem that currently limits the application of real-time hybrid simulation technique. It will lead to an efficient and effective assessment tool that will enable the real-time hybrid simulation technique to be applied in the laboratory to its full potential. The project will help to build international collaborations and enhance the research infrastructure at the School of Engineering at San Francisco State University, one of the nation?s most ethnically and culturally diverse universities. It will be integrated with the servo-hydraulic equipment acquired through a recent NSF-MRI grant at SFSU and will engage undergraduate and graduate researchers in current aspects of earthquake engineering research. The project will also reach out to students from Cañada College, a premier Hispanic-serving institution, to extend the impact of existing NASA CiPair and DoE CalSTEP programs and provide these students with unparalleled opportunities in earthquake engineering research.
