ANALYSIS OF RESEARCH METHODS FOR DETERMINING THE FIRE OF WOODEN BEAMS WITH LINING OF FIRE PROTECTIVE PLYWOOD

Abstract

Until now, scientists have considered only situations in which the ambient temperature has not changed over time. In the conditions of a fire, especially at its initial stage, such approximation is far from reality. Therefore, it is necessary to consider the process at non-stationary ambient temperature. This task is extremely difficult. Its solution was obtained by a number of Ukrainian scientists, and foreign studies have been developed for the case of heating wooden structures with an environment with a temperature that varies according to the standard temperature regime. In this article, we have analyzed all existing experimental and calculation methods for calculating the limit of fire resistance of wood-beam-lined wood. The analysis took into account the features of each method to achieve the most accurate estimates of possible research errors and the range of possible parameters of the specified indicators needed to determine the limit of fire resistance of wooden structures, taking into account the hygroscopicity of the material. In addition, the thermal and strength characteristics were calculated for the standard temperature curve, as well as for the real fire model. The developed algorithms are implemented in the software environment of the computer system MathCAD. For the decision the method of half division which was realized by algorithm which is offered at restrictions which are imposed on the received roots by a range of possible temperatures of heating of samples was used. According to the obtained results, the errors of the obtained researches in different methods for determining the limit of fire resistance for wooden beams with fire-retardant cladding with fire-retardant plywood were determined.