Temperature development of aluminum alloy members considering fire radiation

Abstract

This paper contributes to providing evidence for calculating the temperature development of aluminum alloy members in fire conditions based on theoretical and experimental analysis. Firstly, the theoretical calculation methods are reviewed. The difference between the compartment fire scenario and the large-space fire scenario is highlighted, where the fire radiation is less absorbed by the smoke in the latter. The calculation methods of the radiative heat flux based on the surface and point assumptions, as well as the method recommended in the Eurocode, are introduced. Subsequently, the fire test aiming to explore the temperature development of aluminum alloy members in large-space fires is described and discussed. The test results verified that ignoring the radiative heat flux will lead to an unsafe prediction of the temperature of the members. Then, based on the comparison of the test data and the prediction results calculated by the theoretical methods using the initial parameter values specified in the Eurocode, it is found that the Eurocode method is too conservative. Finally, the Eurocode method is modified, and the calibration of the thermal parameters is performed using the genetic algorithm based on the experimental data. The optimal values of the convective heat transfer coefficient, the emissivity of the aluminum alloy member, and the coefficient of the smoke absorption factor are 50.00 W m−2 K−1, 0.2422, and −0.00061, respectively.