Cure-induced temperature gradient in laminated composite plate: Numerical simulation and experimental measurement

This paper presents numerical simulation and experimental measurement on cure-induced temperature distribution in the AS4/8552 laminated composite plate to identify the influence factors for the formation of temperature gradient. Numerical heat transfer analysis on 5.4 mm thick AS4/8552 laminated composite plate cured on the invar tool was examined with a consideration of the thermal boundary conditions on the invar tool and interfacial heat transfer conditions, followed by an experimental measurement on the temperature gradient by embedding the encapsulated FBG sensors into the sample. The results show the prescribed temperature condition is relatively suitable for the surface of invar tool, and relatively good and bad interfacial heat transfer conditions respectively occur before cool-down stage and in cool-down stage. Further numerical simulation on the temperature gradient of laminated composite plate cured on the aluminum tool and thicker plate cured on the invar tool reveals that the material type of tool and part thickness heavily affects the magnitude of temperature gradient and temperature overshoot during curing.