Free vibration properties of novel sandwich plates with a layered and rotational core

Abstract

The layered sandwich plate structure is widely used in various fields due to its lightweight and high-strength characteristics. To further enhance the functionality of these structures and expand their application areas, this study investigates the impact of an innovative method for adjusting the interlayer angle. This study adopts experimental analysis and numerical simulation methods, taking honeycomb core and grid core as examples, to explore the influence of interlayer angle on the first 9 natural frequencies and vibration modes of bilayer and tri-layer circular sandwich plates, and explain the mechanism of the influence of interlayer angle on the structural natural frequency through theoretical analysis. The results indicate that 1) at different angles, the natural frequencies of the same order vibration modes exhibit significant differences. For instance, in the case of the grid core, the minimum change rate of the natural frequency can exceed 10%, and the maximum can reach 16.68%; 2) compared to the unadjusted layered plates, which exhibit localized deformation in higher-order vibration modes, the stiffness distribution becomes more uniform after rotation, transforming the vibration modes into overall continuous deformations; 3) the proposed method allows for considerable changes in natural frequencies of various orders while maintaining stable structural mechanical properties without adding weight. This effectively avoids resonance with the working environment and promotes uniform stiffness distribution, making the structure suitable for use in more demanding stable environments.