Abstract: The way of artificial accelerated aging to simulate hygrothermal environment was used to investigate the effect of the bonding property of GFRP and paulownia wood in the environment. And, the DCB method was used to test the interfacial properties of the GFRP paulownia sandwich structure. Based on the energy release rates from the test data, the effect of the hygrothermal environment to the interface toughness of the GFRP paulownia sandwich structure was analyzed. Moreover, the tensile property change of paulownia and GFRP in the hygrothermal environment was studied. It was concluded that after 90 days hygrothermal aging, the energy release rate of the paulownia GFRP sandwich composite structures was declined by 32.3%, and the tensile strength of the paulownia cores was decreased by 11.6%. Meanwhile, the tensile modulus of GFRP laminates was reduced by 11.0%.

Key words: glass fiber reinforced composites, paulownia, bonding, energy release rate, sandwich structure