Approach for Modeling Fire Insulation Damage in Steel Columns

This paper presents an approach for modeling the fire insulation damage in steel columns. Both experimental and numerical studies were carried out to investigate the failure pattern and damage phenomenon of fire insulation on steel columns under monotonic and cyclic loads at ambient conditions. As part of the experiments, three fire-insulated steel columns were tested, and the horizontal load and displacement at the top of the column were monitored. The test results show that the adhesion of fire insulation with steel columns is generally weak and that the fire insulation peels off from the column surface under large moments induced at the ends of the column. Under cyclic loading, the adhesion of fire insulation weakens significantly because of the damage-accumulation effect. A finite-element model was developed to evaluate interlaminar stress between the steel plate and the fire insulation, and the effect of critical factors on insulation damage was studied. Results from experimental and numerical studies are utilized to develop an approach for modeling the fire insulation damage in steel columns. In this approach, two damage criteria, namely, maximum stress and distortion energy, are considered for evaluating the insulation damage and damage length. Results from case studies indicate that either of the damage criteria can be applied for evaluating insulation damage and also that both of the criteria predict similar damage patterns.