Research Spotlight: Effect of Boundary Conditions on the Creep Buckling of Steel Columns in Fire

2017 Annual Stability Conference Presentation

Session SS2B – Technical Presentations: Stability at Elevated Temperatures
Tuesday, March 21, 2017
3:15 pm

Effect of Boundary Conditions on the Creep Buckling of Steel Columns in Fire

A computational study using Abaqus was performed to investigate the influence of boundary
conditions on the creep buckling behavior of steel columns at elevated temperatures of fire. W12×120
wide flange columns with the unsupported length of 240 inches are used in the simulations. Thermal
creep of steel is modeled following equations proposed by Fields and Fields for the creep of ASTM A36
steel. Four different classical support conditions and seven imperfection amplitudes are considered to
quantify the effect of boundary conditions on the time-dependent strength of steel columns in fire.
Thermal restraints, both axial and rotational, were ignored in the analyses. Representative results from
creep buckling tests simulated at 500 °C are presented and discussed. Results from creep buckling
simulations presented in this paper indicate that the rotational and translational restraint at the column
ends along with the initial crookedness of the column have a significant impact on the predictions of the
time-dependent strength of steel columns subjected to fire.

Mohammed A. Morovat, Michael D. Engelhardt and Todd A. Helwig, University of Texas at Austin, Austin, TX