Analysis of evaluation methods of fire resistance of steel building structures, taking into account the effect of heat transfer with adjacent structures

Abstract

Purpose. To analyze the methods for assessing the bearing capacity of steel structures, taking into account heat exchange with adjacent building elements.

Methods. Modeling in the system of finite element analysis, theoretical analysis.

Findings. The ANSYS finite element analysis system has solved the heat engineering task of fire resistance of steel fire-protected structures, taking into account the adjoining concrete coating. The analysis of methods of assessing the bearing capacity of steel structures is carried out, taking into account heat exchange with adjacent building elements. The advantages and disadvantages of the considered methods are determined: the methods can take into account the adjoining of adjacent building structures as an ideal thermal insulation from the adjoining side; by applying increasing fire resistance coefficients in cases where the temperature of the steel section or its elementary areas does not exceed 400 ℃. Some of the considered methods take into account heat exchange with adjoining adjacent elements by introducing coefficients for adjoining elements made of concrete or composite slabs. At the same time, steel structures can also adjoin elements made of other materials. The accepted temperature for determining the coefficient of yield strength reduction according to the analyzed sources leads to different values of the bearing capacity, which indicates the need for experimental studies to clarify the optimal values of the accepted temperature.

Application field of research. The results obtained can be used to solve the problems of fire resistance of steel structures with fire protection of the outer surface, taking into account heat exchange with adjacent building structures and elements in the design and construction of buildings and structures.