Finite-Element Modeling for Seismic Damage Estimation of Suspended Ceiling Systems

The seismic qualification and seismic performance assessment of suspended ceiling systems have been traditionally conducted through large-scale shake table testing. This experimentally-based approach not only involves significant financial and time resources but is also not flexible to evaluate several configurations of suspended ceiling systems. As an alternate approach, this paper discusses the development of a general finite-element (FE) model of suspended ceiling systems that accurately captures the propagation of damage observed during full-scale shake table testing using the commercial finite-element analysis software, Abaqus/Explicit. The results of the large-scale shake table testing on suspended ceiling systems conducted at the University at Buffalo as part of the NEES nonstructural project were used to validate the FE model. The major components of suspended ceiling systems such as grid runners, ceiling tiles, and hanger wires were modeled and assembled with significant detail in the FE model. The properties of the connections between the grid runners, which are vital for capturing the seismic behavior of suspended ceiling systems were derived numerically. A user-defined subroutine was incorporated in the Abaqus/Explicit software framework to capture the multidirectional pinched hysteretic behavior of the connections between grid runners. An illustrative example of the application of the proposed FE model to develop robust numerically generated fragility curves for suspended ceiling systems is presented.