Determination of Temperature Histories for Analysis of Structural Response to Fire

May 28, 2015
Publication: Structures Congress Proceedings
Author(s): Kevin LaMalva Morgan Hurley

Uncontrolled fire exposure represents a low-probability and potentially high-consequence event. The emerging field of structural fire engineering involves the explicit design of structural systems to adequately endure thermal load effects caused by uncontrolled fire exposure using rationally-allocated means of protection and potential modifications to preliminary structural system designs. Thermal load effects from fire exposure may include thermal expansion/contraction, reduced material stiffness and strength, and loads induced by thermal restraint. Under these conditions, it is critical that structural systems remain stable to fulfill required performance objectives. This paper examines requisite analysis tasks that precede the determination of structural response to fire exposure. Specifically, the determination of temperature histories of the structural system involves the following: quantification of the fuel loads, evaluation of structural design fires, and determination of the structure’s thermal response. The National Fire Protection Association (NFPA) has recently developed a standard that establishes a basis for selecting fuel load density and distribution. Also, the Society of Fire Protection Engineers (SFPE) has recently developed two standards that provide methods to determine time-dependent thermal boundary conditions on a structural system due to fire exposure, and the resulting thermal response of a structural system. Based upon the thermal response, the structural response to fire exposure may be determined.