Plastic Axial Load and Moment Interaction Curves for Fire-Exposed Steel Sections with Thermal Gradients

Abstract

Current practice for the design of steel beam-columns (i.e., members under combined axial load and bending) subject to fire is to calculate the capacity of these members assuming a uniform temperature distribution through the depth of the section. This assumption may be acceptable for some members, but there are cases where the member will be heated nonuniformly, thereby developing a thermal gradient through its depth. This paper analyzes the effects of thermal gradients on the combined axial load