Abstract: The metallic foam core of lightweight composite sandwich plates undergoes significant deformation along the thickness direction under shock loading, and hence the transverse normal and shear compressions of the core must be considered. A higher-order theory is used to analyze the transverse normal and shear strains of the core, whilst the Kirchhoff theory is used to analyze the thin composite facesheets because of their high-stiffness. The Hamilton's principle is used to obtain the equations governing the vibration performance of the sandwich plate. The extended Galerkin's method is used to solve the governing equations to obtain the vibration equation of the sandwich plate suitable for numerical analysis. The fourth-order Runge-Kutta method is employed to solve the transverse dynamic displacement of the sandwich plate within the elastic range. The inherent frequency of the sandwich plate is compared with the results of finite element method. Finally, the capacity to absorb energy of the sandwich plate is discussed by using the higher-order theory, and the influence of key system parameters is explored. The results show that the whole structural stiffness is affected by changing the ply angle of the facesheets and the thickness of the core, influencing the vibration characteristic of the sandwich composite; the structural vibration is weakened as energy is dissipated by the material damp; and the metal foam core absorbs most of the energy due to the transverse normal and shear compressions.

Key words: oscillation and wave, sandwich plate with metal foam core, transverse compression, shear deformation, vibration performance, energy absorption