Based on the material point method (MPM) and the finite difference method (FDM), a coupled finite difference material point (CFDMP) method is proposed for modelling the 3D high explosive (HE) explosion problems. The CFDMP method is developed through a bridge region to combine the advantages of the FDM and MPM. It solves a 3D HE explosion and its interaction with the surrounding structures by dividing the problem domain into FDM region and MPM region in space. FDM is employed to simulate the region where the detonation products disperse into the surrounding air, while the FSI region is simulated by MPM. A bridge region is employed to exchange the information. In several numerical tests, predictions of the proposed method tests are in good agreement with those of empirical formula and experiments. Furthermore, several cases of air explosion and its interaction with honeycomb sandwich panels are simulated by using CFDMP. The effects of honeycomb's geometry, dimension and material are studied to develop a qualitative law of the anti-explosion performance of honey sandwich panels, which would be helpful to design the honeycomb sandwich panel structures.
