Procedure for simplified analysis of perimeter columns under fire

Several reports and papers have identified a need for developing simple procedures to predict the response of structures in fire. Several performance-based models to calculate the performance of individual heated steel members have been previously developed. However, few approaches have developed simple methodologies for a frame-based analysis of steel structures exposed to fire. This paper shows a two-pronged procedure that predicts the behavior of a column on the perimeter of a building, considering both the individual member response (including thermal gradients) and the global response (including the interactions of adjacent members). All methods proposed in the paper are closed-form (i.e. they require no iteration) and can therefore be solved via spreadsheet or a simple mathematical algorithm. The framework is sufficiently simple for use in codified structural-fire design and could be included in a reference of performance-based analysis methods for steel structures. Although it addresses the performance of a specific member type (perimeter columns), the proposed framework has potential as a blueprint for the targeted performance-based analysis of other members types, such as floor beams.