Bending behavior of sandwich beam with tailored hierarchical honeycomb cores

It is challenging to maintain the lightweight performance of sandwich structure while at the same time to obtain high bending stiffness and strength. In this study, sandwich beams with hierarchical honeycomb cores were proposed. Corresponding mechanical responses bsubjected to three-point bending load were explored and compared with that of the sandwich equipped with conventional honeycomb core by means of numerical simulation. Theoretical solutions of equivalent bending stiffness coincide well with numerical results. Scaling effect of vertex cell and cell size on the hierarchical honeycomb sandwich was investigated. Two tailored hierarchical patterns were proposed by replacing the hexagonal vertex cells with circular and square cells. Compared with the conventional counterpart, the hierarchical sandwich beams offer higher load-bearing capacity. Distinctions of bending strength of each configuration demonstrate different influences of tailored hierarchical cores on enhancing bending resistance ability. There are more local interactions of cells for hierarchical structures. The local improvement promotes more cells to withstand load and the whole sandwich beam can be globally strengthened.