Mechanics model of inner core debonding of interface-reinforced composite honeycomb sandwich beam

Enhanced face-core interfacial bonding performance increases the sensitivity of the structure to core defects. The debonding failure of the inner core in an interface-reinforced composite honeycomb sandwich beam is studied through theoretical modeling and experimental testing. Utilizing the principles of minimum potential energy, Timoshenko's beam theory as well as the Extended High Order Sandwich Panel Theory (EHSAPT), a theoretical model is formulated to clarify the mechanism of inner core debonding. The exponential cohesive zone model (CZM) is used to represent the interfacial mechanical responses of both the face-core and inner core interfaces. Additionally, the theoretical model incorporates the mechanical mechanism of dual crack propagation. The interface-reinforced composite honeycomb sandwich beams are fabricated and the double cantilever beam (DCB) experiments are carried out to reveal the debonding mechanism. The theoretical findings are in accordance with the experimental data when comparing the load displacement curves and the debonding mode.