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2-D Analysis of a Building Frame Under Gravity Load and Fire.

pdf icon 2-D Analysis of a Building Frame Under Gravity Load and Fire. (147 K)
Duthinh, D.

Computational and Experimental Engineering Sciences International Conference (ICCES). ICCES'04. Proceedings. July 26-30-2004, Maderia, Portugal, 1-6 pp, 2004.


high rise buildings; steel structures; building collapse; fire behavior; gravity; fire load; material properties; temperature


A two-dimensional finite-element model is developed that provides some insight into the behavior and collapse of high-rise steel buildings with open web floor systems. For one prescribed temperature distribution that corresponds to a two-story, quarter-span fire, the diagonals of the heated trusses buckle inelastically, causing considerable sag in the fire floors. This behavior puts a high tension demand on the truss connections to the perimeter column, which remains at moderate temperatures in this model and does not experience buckling. Our analysis is based on temperatures and material properties that were selected for illustrative purposes. Therefore no claim is made as to its applicability to any specific structure. The objective of this paper is to present an approach to the analysis of a tall steel building frame similar to the analysis by Usmani et al. For the purpose of comparison with other published work, and to use one specific example to illustrate the analysis method, the data used in this paper are based on infonnation from Reference 2. The choice of a 2-D model is justified by the need to perfonn simple but infonnative calculations covering a wide variety of conditions. We modeled the structural system independently of connection details. Connections are outside the scope of the analysis presented in this paper.