Performance enhancement of sandwich panels with honeycomb–corrugation hybrid core

• Performance of a honeycomb–corrugated hybrid sandwich subjected to out-of-plane compression, transverse shear, and three-point bending is evaluated.
• The strength and energy absorption of the sandwich are dramatically enhanced.
• The enhancement is attributed to the positive interaction effects of corrugated plates and honeycomb cell walls on mutual deformation constraints.

The concept of combining metallic honeycomb with folded thin metallic sheets (corrugation) to construct a novel core type for lightweight sandwich structures is proposed. The honeycomb–corrugation hybrid core is manufactured by filling the interstices of aluminum corrugations with precision-cut trapezoidal aluminum honeycomb blocks, bonded together using epoxy glue. The performance of such hybrid-cored sandwich panels subjected to out-of-plane compression, transverse shear, and three-point bending is investigated, both experimentally and numerically. The strength and energy absorption of the sandwich are dramatically enhanced, compared to those of a sandwich with either empty corrugation or honeycomb core. The enhancement is induced by the beneficial interaction effects of honeycomb blocks and folded panels on improved buckling resistance as well as altered crushing modes at large plastic deformation. The present approach provides an effective method to further improve the mechanical properties of conventional honeycomb-cored sandwich constructions with low relative densities.