Study On Stochastic Property Of Temperature-time Process Of Compartment Fire

Modern structural design aims at reliability. Because the ignition and development of fire as well as the response of structure under fire are all stochastic, it is reasonable for structural fire resistance design to adopt probabilistic method. Research on the stochastic properties of the ignition and development of fire is the basis of probabilistic structural fire resistance design. This dissertation studies the fire ignition probability, parameters influencing fire development and stochastic properties of temperature-time process. The main jobs and conclusions are as follows:(1) A review of the research in the behavior of compartment fires is conducted. Emphasis is given to post-flashover fires which are the main research subject of this dissertation.(2) The probabilistic models of fire ignition are summarized. These models are classified into two categories: macro models and micro models. It is suggested that probabilistic structural fire resistance design adopt macro models.(3) From the angel of practical need of fire-resistance design of structures, the parametric models of fully-developed compartment fire are reviewed. Based on the analysis of the parameters, fire load density, ventilation factor and thermal absorptivity are deemed to be random parameters. Probability distribution models of these random parameters are established.(4) Based on Monte Carlo simulation and numerical method, the characteristics of temperature-time process are studied. The probabilistic model of duration of heating phase is put forward, and the probabilistic characteristics of the temperature-time process are also given. Computer zone model is adopted to verify the results produced by the model. Finally, an example is provided to demonstrate how to use the model.