Post fire performance of galvanized cylindrical shells for buckling failure

Abstract

This study examines the impact of anti-fire paint with different thicknesses of 100, 200, and 400 microns on the post-fire behavior of cylindrical tanks under external pressure. For this purpose, we investigate the buckling modes of the cylindrical tank specimens after they are exposed to fire. Different fire temperatures of 300, 450, and 600 ℃ were investigated. A total of 22 specimens were fabricated in the laboratory. The specimens have been divided into three groups, the first group without any anti-fire, the second group include the anti-fire paint on their inner skin and the last group have the anti-fire paint both on inner and outer faces of the tank. In the second part of the study, to determine the effects of anti-fire paint numerically, the finite element models were created in Abaqus software. Numerical models were verified by Experimental data, with an error rate at initial buckling 5.4%, overall buckling 6.17% and collapse 7.88%. The results showed that the samples with 100-micron-thick anti-fire paint on both outer and inner surfaces did not show any significant difference compared to unpainted specimens under buckling load. However, the cylindrical specimen with 200-micron-thick anti-fire paint on both outer and inner surfaces was found to be fire resistant up to 450 ℃ and displayed similar behaviors with the perfect one (unpainted and not exposed to fire). Moreover, the specimens with 400-micron-thick anti-fire paint were also found to be resistant to fire up to 450°; however, the collapse loads of these specimens were greater than the overall buckling load of the specimens with 200-micron thick anti-fire paint. Numerical and experimental results show a good agreement, the stress distribution and plastic equivalent strain values were parallel with the buckling load capacity of the specimen. As a result, the thickness of the anti-fire paint directly affects the fire resistance of cylinder steel, and with a validated finite element model, it is possible to predict the paint thickness that can withstand specific fire temperatures in large shell structures.