▎ 摘　　要

Although extensive studies have confirmed that adding graphene can improve the damping properties of polymer composites, to date, some critical issues, including aggregation, and mediocre surface friction force of graphene, remain unimproved. In this study, nature-inspired sandwich composites are designed and prepared for vibration suppression, where the conventional blended composites and pure epoxy resin specimens are also prepared as a reference. Dynamic mechanical analysis and vibration test results confirm that the damping properties of sandwich composites are superior compared to those of blended composites and pure epoxy, where the loss factor of pure epoxy is 0.067, and those of conventional blended and sandwich composites with the mass fraction of 0.75 wt%o are increased to 0.067 and 0.0942, respectively. The energy dissipation mechanism of competitive behavior is then proposed to interpret the bell-shaped damping variation of sandwich composites with the increasing thickness of core layer. Moreover, polydopamine (PDA) is used to modify reduced graphene oxide (rGO) to enlarge the surface friction force, which improves the damping enhancing capability of rGO. To be specific, the damping ratio of PDA modified rGO reinforced composites with a mass fraction of 0.5 wt%o is 42.2% higher than that of rGO reinforced composites with the same mass fraction. The modification of rGO and the successful preparation of sandwich composites provide a charming strategy for vibration energy dissipation and damping enhancement.