Thermal response study of carbon epoxy laminates exposed to fire

Abstract In this article, a three‐dimensional thermal response model is developed to investigate the thermal behavior of carbon epoxy composite impacted directly by propane flame. The model is established in consideration of heat transfer and energy conservation in which the heat transfer is in the form of anisotropic heat conduction, absorption by matrix decomposition, and diffusion of gas. Arrhenius equation is utilized to present the decomposition process of the materials. The diffusion equation for the decomposition gas is included for mass conservation. The thermal response model is implemented with the UMATHT and USDFLD subroutines via ABAQUS code, from which the temperature, density, decomposition degree, and decomposition rate can be extracted to analysis the process of material decomposition by finite element simulation. The model shows its capability to analysis the evolution of a carbon epoxy composite in fire by the comparison between the numerical and experimental results. Furthermore, the numerical results show that thermal conductivities in different directions of fiber have a significant influence on the heat transfer. In addition, the relationship between the decomposition degree and temperature is correlated with depths, as well as the peak value of decomposition rate and the time to reach that.