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Prototype Model for Simulating Barrier Fire Performance: CFAST.GYPST - For Evaluating the Thermal Response of Gypsum-Panel/Steel-Stud Wall Systems.


pdf icon Prototype Model for Simulating Barrier Fire Performance: CFAST.GYPST - For Evaluating the Thermal Response of Gypsum-Panel/Steel-Stud Wall Systems. (4384 K)
Cooper, L. Y.; Reneke, P. A.

NISTIR 6482; 70 p. February 2000.

Available from:

National Technical Information Service (NTIS), Technology Administration, U.S. Department of Commerce, Springfield, VA 22161.
Telephone: 1-800-553-6847 or 703-605-6000;
Fax: 703-605-6900.
Website: http://www.ntis.gov
Order number: PB2000-104793

Keywords:

predictive models; algorithms; ASTM E119; compartment fires; fire barriers; fire models; gypsum board; steel studs; walls; zone models

Abstract:

Zone-model-type simulations of compartment fire environments, which include the thermal response of barrier/partition structural elements, are discussed in the context of the adequacy of using a one vs multi-dimensional heat transfer analyses for the barriers/partitions. Introductory discussion focuses on the identification of barrier/partition designs and fire scenarios where such a one-dimensional analysis is valid even when a two- or three-dimensional analysis would be required to study the thermal-structural response. The ideas presented are implemented in a prototype model, CFAST.GYPST, an advanced version of CFAST, which uses the algorithm and associated FORTRAN subroutine GYPST, developed previously to simulate the thermal response of fire-environment-exposed wall systems constructed of arbitrary-thickness gypsum panels mounted on either side of vertical steel studs. GYPST was designed as a modular algorithm/subroutine for integration into zone-type compartment fire models and for use in "stand-alone" analyses. CFAST.GYPST is validated by using previously acquired experimental data from ASTM E119 furnace tests of two different, full-scale wall-system designs. This is accomplished by first establishing a particular room fire scenario where the simulated room fire environment closely follows the ASTM E119 furnace environment. It is then verified that, when the upper layer gases are opaque (analogous to a typical wall furnace exposure) and closely track the ASTM El19 temperature-time curve, the CFAST.GYPST-simulated thermal wall-system response compares favorably to the corresponding experimental thermal-response data acquired during the furnace-exposed wall-system tests. In example "real-fire-type" simulations that are relatively-severe (i.e., the upper layer temperature rises above that of the ASTM E119 standard fire for several minutes and then drops below it), CFAST.GYPST is used to calculate the fire environment and associated wall response for each of the above-referenced wall systems for a room geometry and fire energy-release history that is related to that of a newly developing ASTM room fire test standard. For these simulations, the thermal responses of the two wall systems are predicted and then evaluated relative to respective expected fiie resistance.