Temperature distribution patterns of a steel beam with fire protection from gypsum board during fire

The article examines the temperature distribution in steel beams from the HEB 200 profile with fire protection in the form of plasterboard plates under the influence of the standard fire temperature regime. The calculation was carried out in the ANSYS WB software package to determine the dependence of the temperature in the steel structure on the time of exposure to fire. The model allows for a detailed assessment of heat transfer in materials with different thermophysical characteristics, in particular, variable heat capacity and thermal conductivity of steel and plasterboard. The use of plasterboard as a fire-resistant coating is justified by its ability to slow down the heating of steel. This approach makes it possible to significantly increase the fire resistance of steel structures while maintaining their mechanical integrity. The obtained results showed that the maximum temperature in a steel beam with plasterboard fire protection does not exceed 443 °С even with a duration of fire exposure of 60 minutes, which assumes compliance with the fire resistance class R60. The constructed graph of the dependence of the maximum temperature on the time of exposure to fire confirmed the effectiveness of fire protection with plasterboard and the high accuracy of the approximation of the model (the coefficient of de-termination R²=0.9923), which indicates the reliability of the results. The proposed model and approach can be used to assess the fire resistance of other steel structural elements, in particular, to select optimal fire-resistant materials. The research is relevant in the context of the development of cost-effective and effective methods of protecting building structures from the effects of high fire temperatures. The method of modeling fire protection in steel beams provides an opportunity to determine the temperature regimes that occur in real fire conditions, and to develop recommendations for increasing the fire resistance of steel structures, especially in modern buildings, where the optimization of material and resource costs is important.