MCEER-11-0005 | 10/12/2011 | 218 pages
TOC: The table of contents is provided.
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Keywords: Cold-formed steel. Steel-frame structures. Gypsum. Partition walls. Essential facilities. Hospitals. Seismic performance. University at Buffalo Nonstructural Component Simulator (UB-NCS). Hysteretic models. Incremental dynamic analyses (IDA). FEMA P695. Lateral force-resisting systems.
Abstract: The first phase of the NEES Nonstructural Gran Challenge Project tested full-scale cold-formed steel-framed gypsum partition walls using the University at Buffalo Nonstructural Component Simulator (UB-NCS). A description and experimental results for 22 different partition wall configurations is given. The experimental data are used to populate an extensive seismic fragility database for cold-formed steel-framed gypsum partition walls. Parameters for a tri-linear hysteretic model, aimed at reproducing the in-plane mechanical behavior of partition walls, are determined from the experimentally obtained force-displacement curves. Recommended parameters for in-plane walls are given for individual configurations and cold-formed steel-framed nonstructural partition walls. The calibrated partition wall models are combined with the structural model of an existing four-story steel moment-resisting frame (MRF) medical facility to demonstrate the effect on dynamic properties. As the period of the structure reduces due to the increased stiffness from partition wall systems, reductions in drift and absolute floor accelerations are observed. The assumption that these wall systems have negligible impact is disproven by the use of incremental dynamic analyses (IDA) performed according to the FEMA P695 methodology. These analyses show that including the contribution of steel stud gypsum partition walls to the lateral force-resisting system increases the building collapse safety margin by 32 percent.