A thermal-mechanical model has been developed to calculate the tensile strength and time-to-failure of glass fibre reinforced polymer composites in fire. The thermal component of the model considers the effects of heat conduction, matrix decomposition and volatile out-gassing on the temperature-time response of composites. The mechanical component of the model considers the tensile softening of the polymer matrix and embrittlement of glass fibres in fire, with strength loss of the fibres analysed as a function of temperature and heating time. Comparisons of model predictions with experimental data will be presented. The strength reduction mechanism of glass fibres at elevated temperatures will be discussed in detail. It was found that fracture mirror sizes on the glass fibre fracture surfaces are related to fibre strength after high temperature exposure. As a result, it can be proven that the glass strength reduction at high temperature is controlled by the growth of surface flaws.
Dr Feih is a Research Fellow in composites at RMIT University. She has a MSc degree from Cornell University and a PhD from Cambridge University in composites engineering. Following graduation, she spent three years as a research engineer at the National Research Laboratory, RISÃ˜ (Denmark) before joining RMIT in 2005 to work on the fire performance and structural modeling of composites. Her research interests include fire modeling of composites, damage/cohesive element modeling of composites, and fiber/matrix interface properties. Dr Feih has published over 30 journal and international conference papers