51³Ô¹ÏÍø

Abstract:

Real-time hybrid simulation (RTHS) is an advanced cyber-physical simulation technique that combines physical testing with computational modeling to evaluate the dynamic response of structural systems subjected to extreme hazards. Components that are difficult to model accurately are tested experimentally, while the remainder of the structure is represented numerically. The physical and numerical substructures are coupled in real time through their interface degrees of freedom, enabling realistic assessment of complete structural systems and response modification devices.
Lehigh University hosts the NSF-funded Natural Hazards Engineering Research Infrastructure (NHERI) Lehigh Experimental Facility, which specializes in large-scale, multi-directional RTHS. This presentation highlights recent research on the seismic performance of steel buildings equipped with nonlinear viscous dampers. Large-scale RTHS was conducted to investigate the coupled behavior of the damping system, structural frame, and soil–foundation interaction (SFI). Performance-based design strategies, including reduced design base shear strength permitted by ASCE 7 for structures with supplemental damping, were evaluated. Neural network models were developed and integrated into the RTHS framework to accurately represent SFI effects, with the primary objective of limiting structural and nonstructural damage through reduced seismic story drifts.
The presentation will introduce recent advances in RTHS methodologies developed at Lehigh and demonstrate their application through experimental studies of damped steel frame buildings subjected to strong earthquake ground motions. Particular emphasis will be placed on the influence of design base shear strength on peak and residual story drifts and on the interaction between supplemental damping devices and the lateral force-resisting system.

Bio:

James M. Ricles is the Bruce G. Johnston Professor of Structural Engineering in the Department of Civil and Environmental Engineering at Lehigh University, where he has been a faculty member since 1992. He also serves as Director of the ATLSS Engineering Research Center and the NSF-funded Natural Hazards Engineering Research Infrastructure (NHERI) Lehigh Experimental Facility.
Dr. Ricles received his B.S. and M.S. degrees from the University of Texas at Austin and his Ph.D. from the University of California, Berkeley. His research focuses on structural resilience, emphasizing advanced computational frameworks and large-scale, multi-directional real-time hybrid simulation (RTHS) for evaluating complex structural systems subjected to extreme hazards. His research on neural network-enabled RTHS was recognized as one of the Top Viewed Articles of 2025 in Earthquake Engineering and Structural Dynamics.
He is a registered Professional Engineer in California, Editor-in-Chief of Engineering Structures, and a member of the Editorial Advisory Board of Earthquake Engineering and Structural Dynamics. His honors include the NSF Presidential Young Investigator Award, the ASCE Raymond C. Reese Research Prize, the AISC Special Achievement Award for innovations in structural resilience, the Lincoln Arc Welding Foundation Award for Outstanding Achievement in Arc Welded Design, and the Engineering Structures 2024 Best Paper Award in Structural Analysis and Design.

Open to all. Attendees external to 51³Ô¹ÏÍø need to register by email. 

Time: 12:00