Study on Thermal Response of Adhesively Bonded Honeycomb Sandwich Structure in High Temperature

Thermal response of the honeycomb sandwich structure was evaluated using the steady-state method at different temperatures ranging from 100 degrees C to 400 degrees C. The results showed that effective thermal conductivity decreases when the temperature set is over 300 degrees C, and the critical temperature is about 310 degrees C. As a result, a set of experiments was conducted to observe the inner structure of the sandwich in a quest to understand why the thermal conductivity decreases. A black substance was found, and it adhered to the interfaces between the faces and the core where the adhesive is located. A series of experiments were carried out to study the thermal response of the adhesive. The TG curves showed that the total mass loss of adhesive can reach 90% due to the thermal decomposition, which can absorb a portion of energy. Meanwhile, the black substance was also produced during the TG measurements and its carbon content reached 64.38%.