Effect of heat losses on fire resistance test results for metal

The effect of heat losses on the fire resistance of a flat metal plate tested in a standard fire regime is examined. The dependence of the temperature dynamics of the plate with and without a coating on the thermophysical properties of the insulation on exposure to fire heat loading is studied numerically. The results of the study indicate the need for using a coupled formulation of the problem and standardizing the type and thermophysical properties of the thermal-insulation material for a correct modeling and testing of the heat and fire protection of the metal plate, especially in the case of a small plate thickness. Integral criteria are proposed to characterize the heat losses and insulation efficiency on the rear surface of the plate.