Numerical Investigation of the Fire Behavior of Storage Rack Systems Protected by Intumescent Coating

Abstract

Using a finite element strategy, this study investigates the behavior of beam-to-column connections in storage rack systems exposed to high temperatures. The purpose of this research was to develop moment−rotation (M−θ) curves after painting various structural members with varied configurations in order to evaluate the performance of intumescentcoated beams, uprights, and connectors, which are components of storage rack systems. Within the scope of this work, finite element analyses were carried out in two stages. First, thermal analyses were performed using the transient thermal analysis system of ANSYS Workbench software to estimate the ultimate temperatures of the beam, upright, and connector, which were painted with 1 mm thick paint and exposed to standard (ISO-834) fire. The results were then compared to the Eurocode 3 Part 1.2 with a satisfactory agreement. In the second stage of the analysis, a total of 9 possible alternative models were investigated in the static structural analysis system, reflecting the effect of applying fire protection to the different portions of the rack system. Since the most critical stress level is achieved around the connector tabs, it has been observed that protection of the connector in individual or binary conditions provides higher performance while protection of the beam causes divergent joint behavior. Additionally, comparison of fully protected and unprotected conditions presents an increment of more than 7% on the joint's ultimate moment capacity and initial stiffness, which is an explicit contribution of the intumescent coating to fire resistance.

Investigation of the Structural Behavior of Reinforced Concrete Beams at Elevated Temperatures

“…Considering previous studies, the ISO-834 standard fire effect was used as the heating regime. 14,15,18,19,31,34,35 Then, for the purpose of examining the effects of heating on the specimens, they were subjected to the loading.…”

“…The control specimens were tested at room temperature (23 °C) whereas others were exposed to the elevated temperatures and left to cooling. Considering previous studies, the ISO-834 standard fire effect was used as the heating regime. ,,,,,, Then, for the purpose of examining the effects of heating on the specimens, they were subjected to the loading.…”

Mechanical Properties of S235 Steel Protected with Intumescent Coatings Under High Temperatures: An Experimental Study

“…Despite the advances in fire-resistant materials, significant vulnerabilities still exist, particularly with cold-formed thin-walled steel profiles. These profiles, which are commonly used due to their cost-effectiveness and ease of installation, are less resistant to fire compared to their hot-rolled counterparts, a fact that has been well documented in various studies [1][2][3][4][5][6][7][8][9]. For instance, research has shown that a marked decrease in mechanical strength and stiffness occurs as temperatures rise, with critical degradation occurring between 550 and 600 • C [10][11][12][13][14][15].…”

Reformative Effects of Intumescent Coating on the Structural Characteristics of Cold-Formed Steel

“…Their functions have extensively been detailed in previous studies, and formulas have been refined over the last decades to generate an effective protective char. Intumescent process of the coatings can be presented in four steps, basically named as reaction, swelling, char formation, and char degradation Reaction (melting step): when exposed to a heat source and reaches a threshold temperature, the inorganic acid source undergoes thermal decomposition as the surface melts and transforms into a viscous fluid …”

“…Intumescent process of the coatings can be presented in four steps, basically named as reaction, swelling, char formation, and char degradation. 36 Reaction (melting step): when exposed to a heat source and reaches a threshold temperature, the inorganic acid source undergoes thermal decomposition as the surface melts and transforms into a viscous fluid. 31 Swelling (expanding step): after the melting step, endothermic reactions occur by absorbing heat from the substrate and decomposing it, releasing a large number of gaseous products.…”