Temperature Field and Thermal Damage Analysis of Glass Fiber/Epoxy Resin Laminated Plates Under Unilateral Heating Conditions

ABSTRACT To investigate the pyrolysis heat transfer of resin‐based fiber‐reinforced composites in high‐temperature environments, a study was conducted on the unilateral thermal response behavior of glass fiber‐reinforced composites under different temperatures. Subsequently, a two‐dimensional pyrolysis response model was constructed using an ABAQUS UMATHT subroutine, considering in‐plane and thick‐direction heat transfer. Results show that: under unilateral heating conditions, the temperature field of composite laminates exhibits gradient variations along the thickness direction and in the in‐plane direction. When the temperature of the exposed surface reaches the material's initial thermal decomposition temperature, the material begins to undergo pyrolysis reactions, accompanied by internal delamination of the laminates. Infrared thermal imaging accurately measured the temperature field of the unexposed surface of laminates and detected the laminates' internal stratification. The temperature change history estimated by the pyrolysis response model corroborated with the actual measured values, indicating that the pyrolysis response model can predict the temperature field variation characteristics of laminates under single‐sided heating conditions. In addition, the initial thermal decomposition temperature calculated by the pyrolysis response model also matched the thermogravimetric test results and accurately evaluated the change in density and the material's pyrolysis damage behavior.