Abstract
The main purpose of this study is to quantify both collapse temperatures and probability of occurrence on collapse modes for a steel subassemblage, which consists of upper and lower columns and a beam subjected to fire, in case of considering the variations in steel strength at elevated temperature. Numerical analyses using Monte Carlo (referred to as MC) method are conducted to estimate the collapse temperature. For estimation on buckling temperature of the heated column, an equation (10) giving buckling strength at the elevated temperature is proposed. From observation of the MC analytical results, the following has been clarified: the collapse modes of the subassemblage are easily changed in the case when there are little difference among the theoretical collapse temperatures of each collapse mode, on the other hand, in the case when the difference is approximately ≧ 100 °C, the collapse mode approximately agrees with the determinate theoretical collapse mode.
