Fire Response of Loaded Composite Structures - Experiments and Modeling

Abstract

In this work, the thermo-mechanical response and failure of loaded, fire-exposed composite structures was studied. Unique experimental equipment and procedures were developed and experiments were performed to assess the effects of mechanical loading and fire exposure on the service life of composite beams. A series of analytical models was assembled to describe the fire growth and structural response processes for the system used in the experiments. This series of models consists of a fire model (to predict the heat flux to the fire-exposed beam), a thermal response model (to calculate the temperature distribution within the beam due to this heat flux), a stiffness-temperature model (to calculate the loss in stiffness at elevated temperatures), a mechanical response model (to compute the strain distribution within the loaded beam), and a material failure model (to calculate the strain at which the beam is expected to fail). Each of these models is independently validated by comparing predictions with experimental results. The models are then used to predict the times-to-failure for beams over a range of fire and loading conditions. The predicted failure times agree fairly well with experimental results, but it is expected that the agreement could be improved with improvements to the first model in the series - the fire model.