The performance of structural steel beams subject to a localized fire

Published

June 7, 2016

Author(s)

Lisa Choe, Selvarajah Ramesh, Chao Zhang, John L. Gross

Abstract

This paper presents the results from the open flame, localized fire tests conducted on the 6.17-m long, simply supported W16×26 beam specimens. The cross sections at midspan (i.e. expected plastic hinge zone) of the beam specimen directly exposed to the natural gas fire. The tests were divided into two parts: (1) the fire-thermal tests to evaluate the effects of the prescribed heat release rates (HRR), provided by the 1-square meter natural gas burner, on the thermal responses of the specimen and (2) structural-fire test to evaluate the fire effects on the overall behavior and the load-bearing capacity of the specimen. The test results indicated that the prescribed heat release rates from the burner affected the heating rate of the specimen. When the HRR-time relationship of the burner followed the step function, the fire-exposed region of the beam specimen was heated linearly with increasing time of fire exposure. When the HRR was set to a target magnitude of 400 kW throughout the test, the fire-exposed region was heated nonlinearly until it reached a steady-state temperature condition. When the beam specimen was subjected to linearly increasing flexural loads at a maintained HRR of 700 kW, combined flexural and lateral torsional behavior of the specimen was exhibited. The lateral deformations in the compression flange at the fire-exposed critical sections initiated at 120 kN-m, 51% of the plastic capacity at room temperature. The peak moment capacity was achieved at 171 kN-m, 73 % of the plastic moment capacity at room temperature. The test results from the present study would be supplemental to any existing database for developing or calibrating analytical models, which can be eventually used for evaluating the performance of structural members subjected to a localized fire.

Proceedings Title

9th International Conference on Structures in Fire SiF¿16

Conference Dates

June 8-10, 2016

Conference Location

Princeton, NJ, US

Pub Type

Conferences

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Keywords

localized fire, structural steel beam

Citation

Choe, L. , Ramesh, S. , Zhang, C. and Gross, J. (2016), The performance of structural steel beams subject to a localized fire, 9th International Conference on Structures in Fire SiF¿16, Princeton, NJ, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=920583 (Accessed April 25, 2024)