Experimental and numerical research on flexural behavior of fiber metal laminate sandwich composite structures with 3D woven hollow integrated core

The face-core debonding of sandwich structures under bending will affect the overall load-bearing capacity. Fiber metal laminate (FML) sandwich composite structures with 3D woven hollow integrated core (3D core) were prepared by vacuum resin infusion method and thermal molding process. The flexural behavior of the structures was experimentally studied by a three-point bending test and investigated by evaluation of specific flexural strength, flexural rigidity, and ductility. Numerical simulation finite element models of structures with different cores under three-point bending were calculated by ABAQUS/Explicit. Results showed that plastic rotation of the "8"-shaped fibers in the 3D core was the main reason for the failure modes of asymmetric densification. FML as the faceplate of the 3D core can significantly improve its flexural strength, rigidity, and ductility.