A simple method to predict temperature development in a protected steel member exposed to localized fire in large spaces

Summary Temperature development is a key issue for fire protection of steel structures. However, until now, there has been little systematic approach to predict the steel temperature development during the whole process of a localized fire in large spaces. The smoke temperature development in large spaces is different from that in normal enclosure fires as they have lower maximum temperatures and non‐uniform temperature distributions. In the present study, a whole process prediction method for the development of smoke temperatures in a large space localized fire is proposed. The prediction method accurately reflects the temperature curves (in the growing, fully developed and decay phases) and the uniform temperature distribution in large space localized fires. Based on basic heat transfer principles and the proposed smoke temperature development model, a new relationship is proposed to predict the temperature development in a protected steel member exposed to localized fire in large spaces. There is only one variable, t (time), in the proposed relationship, and thus, it is very simple to implement in evaluating temperatures, and it accurately reflects the development of the whole fire process (growing, fully developed and decay phases).