Modelling decomposition and fire behaviour of small samples of a glass-fibre-reinforced polyester/balsa-cored sandwich material

摘要

This publication presents the experimental and numerical methods to model the devolatilization process of a glass-fibre-reinforced polyester/balsa-cored sandwich material on small scale. The fundamental modelling of the source term in pyrolysis-based fire simulations requires as input data the thermochemical properties of solid fuel and the kinetic parameters of the devolatilization process. First, the thermal decomposition of both elements composing the sandwich structure was studied by thermogravimetry coupled with gas analysis, in air and pure nitrogen atmospheres at several heating rates, in order to define a comprehensive multi-step reaction pathway. A differential equation system is defined to model these decomposition processes. The kinetic parameters were then estimated by solving the system of equations by an inverse problem. Second, the fire behaviour of each element was studied separately and then combined in the sandwich structure on the cone calorimeter. In addition, numerical simulations with Fire Dynamics Simulator were performed to gradually assess the ability of the model(s) to reproduce each element composing the sandwich structure. Numerical and experimental results are compared and then discussed. Overall, the model provides a good agreement with the experimental data and encourages to model higher scales.