Structural analysis of composite sandwich plates with enhanced pyramid lattice core using VAM-based reduced-order equivalent model

Abstract

To overcome the issues of low face sheet–core interface strength and out-of-plane bearing capacity in the traditional pyramid lattice sandwich structure, a composite sandwich plate with enhanced pyramid lattice core (CSP-EPL) is investigated. A two-dimensional reduced-order equivalent model (2D-REM) based on the variational asymptotic approach is developed to study its static and dynamic responses. The accuracy and efficiency of the proposed model are verified by comparison with three-dimensional finite element (3D-FEM) results under different boundary conditions, including global static displacement, global buckling, local field recovery, and free and forced vibration. The predicted results of 2D-REM are in good agreement with those of 3D-FEM, and the computational efficiency is improved. Finally, the influence of geometric parameters of type III reinforcements on the equivalent stiffness is thoroughly examined, which helps to further reduce the weight and improve the bearing capacity of CSP-EPL.