Quasi-static mechanical properties of composite lattice sandwich structures with enhanced face panels

Abstract

Interface debonding in sandwich structures usually occurs due to the low interfacial bonding strength. To effectively enhance the bonding strength of the interfaces, the quasi-static out-of-plane compressive and shear mechanical properties of composite sandwich structures with four types of enhanced pyramidal configurations are systematically investigated through theoretical and experimental methods. According to the theoretical predictions under two kinds of loads, the 3D failure mechanism maps are generated and the corresponding specimens are designed and fabricated. Based on several necessary assumptions, acceptable error range between the theoretical and experimental results has been achieved, and the 3D failure mechanism maps are well verified. According to the analysis of the shear experimental results, the sandwich structure with enhanced ribs can significantly enhance the adhesive strength of the interface. Besides, except for the enhanced ribs, the vertical struts existed in sandwich structures with both the enhanced pyramidal configurations II and III can also effectively improve the interfacial bonding strength.