Fire Safety Science Digital Archive

This paper deals with the fire spread within and between wooden buildings in Japan. The relation of the burnt area and the time draws approximately an S-curve. As former theories fail to estimate the real fire spread condition correctly, we have examined a polynomial curve and a logistic one as the most appropriate substitutes. According to the method of MAICE proposed by Dr. Akaike (1973), the optimal degree of the polynomial is shown to be three. But the polynomial does not fit the real fire spread phenomenon because it does not always follow a monotone function. Thus we have suggested that the logistic curve is good enough to explain the fire spread phenomenon. But our model exhibits symmetry at the point of inflection. As the fire spread phenomenon is not guaranteed to have symmetry, we have examined a more general type of logistic curve which describes the fire spread. In case of determining the parameters of the logistic curve, we should strictly use the nonlinear least squares method as we have already reported in our former studies. By analyzing the data of real fire experiment by this method, we have obtained a very significant result, and also wish to refer to the method of improving the determination method of the parameters of the fire spread model.