Thermal response of carbon/phenolic composites under high intensity thermal radiation heating: Experimental and numerical analysis

Abstract In this paper, the thermal response and pyrolysis mechanism of carbon fiber/phenolic plain composite laminates under the thermal radiation were investigated experimentally and numerically. Thermal radiation was generated through aluminum‐oxygen combustion with higher coverage and heat flux density than conventional heat sources such as paraffin, diesel, and propane, allowing for a more realistic simulation of high‐temperature environments. The specimens exhibited damages such as fiber‐char, matrix decomposition, and delamination after the experiment. Then, the thermal/chemical coupling model was implemented by developing finite element codes using UMATHT, DFLUX, and USDFLD user‐defined subroutines based on ABAQUS. The temperature distribution and pyrolysis behaviors of the specimen were calculated, which were consistent with the experimental values. From the numerical results, it could be inferred that the peaks of temperature and pyrolysis rate gradually migrated inward and eventually reached a steady state after heating. Finally, the thermal response of composite laminates at different heat sources was discussed. The results indicated that the temperature and pyrolysis depth increased as the heat flux density decreased at high heat energy. However, these had an opposite phenomenon to decrease with decreasing heat flux density at lower heat energy. Highlights The damage of composite materials under strong thermal radiation was revealed. The temperature and pyrolysis status of materials was predicted numerically. The damage to materials under different thermal radiation loads was compared.