NEES Nonstructural: Simulation of the Seismic Performance of Nonstructural Systems
Nonstructural systems represent 75% of the loss exposure of U.S. buildings to earthquakes, and account for over 78% of the total estimated national annualized earthquake loss. A very widely used nonstructural system, which represents a significant investment, is the ceiling-piping-partition system. Past earthquakes and numerical modeling considering potential earthquake scenarios show that the damage to this system causes the preponderance of U.S. earthquake losses. Nevertheless, due to the lack of system-level research studies, its seismic response is poorly understood. Consequently, its seismic performance contributes to increased failure probabilities and damage consequences, loss of function, and potential for injuries. All these factors contribute to decreased seismic resilience of both individual buildings and entire communities.
Ceiling-piping-partition systems consist of several components and subsystems, have complex three-dimensional geometries and complicated boundary conditions because of their multiple attachment points to the main structure, and are spread over large areas in all directions. Their seismic response, their interaction with the structural system they are suspended from or attached to, and their failure mechanisms are not well understood. Moreover, their damage levels and fragilities are poorly defined due to the lack of system-level experimental studies and modeling capability. Their seismic behavior cannot be dependably analyzed and predicted due to a lack of numerical simulation tools. In addition, modern protective technologies, which are readily used in structural systems, have never been applied to these systems.
This project sought to integrate multidisciplinary system-level studies to develop, for the first time, a simulation capability and implementation process to enhance the seismic performance of the ceiling piping-partition nonstructural system. A comprehensive experimental program using both the University of Nevada, Reno (UNR) and University at Buffalo (UB) NEES Equipment Sites was developed to carry out subsystem and system-level full-scale experiments. The E-Defense facility in Japan was used to carry out a payload project in coordination with Japanese researchers. Integrated with this experimental effort was a numerical simulation program that developed experimentally verified analytical models; established system and subsystem fragility functions; and created visualization tools to provide engineering educators and practitioners with sketch-based modeling capabilities. Public policy investigations were designed to support implementation of the research results.
The systems engineering research carried out in this project will help to move the field to a new level of experimentally validated computer simulation of nonstructural systems and establish a model methodology for future systems engineering studies. A system-level multi-site experimental research plan has resulted in a large-scale tunable test-bed with adjustable dynamic properties, which is useful for future experiments. Subsystem and system level experimental results have produced unique fragility data useful for practitioners.
NEES Nonstructural Project Homepage
National Science Foundation Award Abstract
- Modeling and Seismic Evaluation of Nonstructural Components: Testing Frame for Experimental Evaluation of Suspended Ceiling Systems, A.M. Reinhorn, K.P. Ryu and G. Maddaloni; MCEER-10-0004; 6/30/2010; 182 pages; $30.
- Seismic Evaluation, Parameterization and Effect of Light-Frame Steel Studded Gypsum Partition Walls,
R. Davies, G. Mosqueda, R. Retamales and A. Filiatrault; MCEER-11-0005; 10/12/2011; 218 pages; $35.
- Bayesian Fragility for Nonstructural Systems, by C.H. Lee and M.D. Grigoriu; MCEER-12-0006; 9/12/2012.
- A Numerical Model for Capturing the In-Plane Seismic Response of Interior Metal Stud Partition Walls, R.L. Wood and T.C. Hutchinson; MCEER-12-0007; 9/12/2012.
- Assessment of Floor Accelerations in Yielding Buildings, J.D. Wieser, G. Pekcan, A.E. Zaghi, A.M. Itani and E. Maragakis; MCEER-12-0008; 10/5/2012.
- Experimental Seismic Study of Pressurized Fire Sprinkler Piping Subsystems, Y. Tian, A. Filiatrault and G. Mosqueda
Maddaloni G., Ryu K.P. and Reinhorn, A.M. (2011), "Shake Table Simulation of Floor Response Spectra" in Int. Journal of Earthquake Engineering and Structural Dynamics, 40(6), 591-604 , with "Discussion" by Huang, Chen, and Lu, and "Authors' Reply" (2012) in Journal of Earthquake Engineering and Structural Dynamics, (published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/eqe.1194).
Retamales, R., Mosqueda, G., Filiatrault, A. and Reinhorn, A. 2011. “Testing Protocol for Experimental Seismic Qualification of Distributed Nonstructural Systems,” Earthquake Spectra, Vol. 27, No. 3, 835-856.