Honeycomb Configuration Design for Enhanced Bonding Performance of Sandwich Structures: Failure Modes and Load‐Bearing Capacity

ABSTRACT To enhance interfacial bonding performance of honeycomb sandwich composites, this study proposes novel honeycomb configurations. Three advanced honeycomb core configurations, namely enhanced honeycomb (EH), double‐wall enhanced honeycomb (DEH), and multi‐wall enhanced honeycomb (MH), were designed and fabricated from a conventional normal honeycomb (NH) baseline by modifying key characteristics including cell geometry, wall thickness, and relative density. Failure behaviors under different loading directions were investigated via tensile peel tests and finite element simulations. Results demonstrated that redirecting failure from interfacial debonding to energy‐dissipative modes, namely flange fracture and cohesive failure, significantly improved bonding performance. EH exhibited superior Mode‐I critical strain energy release rate and peak load compared to NH. Increasing the core wall thickness further enhanced bonding performance: DEH achieved peak load improvements of 92.87%, 82.41%, and 111.8% over NH in the L , W ₁ , and W ₂ directions, respectively. Adding more flanges led to MH with higher relative density, achieving increases of 138.06%, 75.04%, and 121.69% in the respective directions. However, higher relative density enabled stronger bonding at the expense of weight. Thus, from the perspective of lightweight design, EH exhibited the highest load growth coefficient.