Bending And Vibration Of Sandwich Plates Based On First/High Order Deformation Theory

Sandwich plates are widely used in aerospace for high strength and stiffness, and also goodproperties of vibration isolation and insulation of sound and thermal. With the development ofmaterial science, better materials were used in the design of sandwich structures. The theory build onthe assumption of Soft-Core by Reissner and Hoff were not adequate to the structure construct by thenew materials.The results show that Reissner theory and Hoff theory not adequate to the bending analysis ofHard-Core sandwich plates. Deng’s theory is satisfied to bending analysis of Hard-Core sandwichplates. Reissner and Deng’s theories ignored transverse stiffness and bending stiffness of surfaces andit adequate decrease quickly when the core is softer and the surfaces are thicken.In present paper, the transverse shear stiffness and in-plane stiffness and bending stiffness alsowere considered to derive the basic equations of sandwich plates. The bending and vibrations ofsandwich plate with four edges simply support and transverse loading supplied on the face werecalculated. The results based on the theory of Reissner and Hoff and Deng Zongbai refined modalwere compared with the present work. The frequencies of vibrations were studied and the results werecompared with NASTRAN. The transverse strains and normal line rotations of mid-surface werestudied during the bending. The differences of bending displacements and transverse strains andnormal line rotations by transverse shear were compared between First-Order and High-Orderdeformation theories.