Modern sensitivity analysis of the CESARE-Risk computer fire model

Abstract

This paper introduces two new modern methods of global sensitivity analysis for computer models: Fourier Amplitude and Sobol, as well as a modern factor screening method: the Morris method. The methods are applied to the sensitivity analysis of the apartment fire module of the CESARE-Risk building fire computer model with eight input factors and door and window open. Two output variables are considered: the maximum temperature reached and the time of onset of untenable conditions. Response surfaces previously derived for the model [Jianguo Qu, Response surface modelling of Monte Carlo fire data, Ph.D. Thesis, Victoria University, Melbourne, Australia, 2003, http://eprints.vu.edu.au/archive/00000260/01/Qu,_Jianguo.pdf] are used to speed up the computations. For the maximum temperature all three methods agree that the most sensitive factors are the window height and width factors, followed by the fuel area factor. The largest interaction was between the length of room and the fuel area factor. For the time of untenable conditions the Fourier Amplitude and Sobol methods agreed that one factor, the flame spread rate, had overwhelming significance. The only significant Sobol interaction was between the width of room and the flame spread rate.