Integrated preparation and compression behavior of novel 3D-Kagome lattice sandwich composite assembled by semi-rigid mortise-tenon joints

Lightweight lattice sandwich composites have shown the excellent mechanical property and potential multi-functionality. As the classic lattice topology, the potential advantage of 3D-Kagome lattice core is well underutilized due to the preparation limitation. In this paper, a modified 3D-Kagome lattice core is designed, which can be sequentially assembled using three specific types of core-rods based on the clever semi-rigid mortise-tenon joints. The method perfectly resolves issues related to the overlapping of 3D-Kagome core-rods and weak connections between face-sheets and lattice cores. The mechanical properties of the Kagome lattice sandwich composites are investigated under out-of-plane and in-plane compression. The variations of out-of-plane compressive curves are analyzed to explore the multiple failure modes and quasi-static energy absorption mechanism. The different deformation patterns under in-plane compression are also recorded to illustrate the stiffness matching effect between face-sheets and lattice cores. Moreover, the effects of geometric parameters on the mechanical behaviors of sandwich structures are studied. Compared to the other lattice materials, the integrated 3D-Kagome lattice sandwich composites with the semi-rigid mortise-tenon joints demonstrate superior compressive properties, deformation tolerance, and energy absorption characteristics. These findings suggest that the sandwich structures with semi-rigid mortise-tenon joint are expected to show good bending and torsional properties.