High frequency vibration analysis of composite sandwich plates with lattice core using Energy Flow Analysis and equivalent homogeneous plate core

Sandwich plates with lattice cores are increasingly employed in industrial applications involving high-frequency vibrations. This research investigates the vibrational behavior of such plates using the Energy Flow Analysis (EFA) method, an approach renowned for its computational efficiency in the high-frequency regime. The governing equations are extended by employing higher-order shear deformation theories (HSDT) for the sandwich core, and the corresponding wave propagation parameters are derived. Relationships for energy density and intensity are established based on classical solutions of the equations of motion, assuming a diffuse field to describe high-frequency wave propagation. The analysis is conducted on sandwich plates with laminated composite face sheets and various lattice cores of different thicknesses. Findings indicate that the EFA method is not only effective for high-frequency vibration analysis but also significantly reduces computational costs. The validity of substituting the lattice core with a homogeneous plate possessing equivalent mechanical properties is also examined, with results demonstrating acceptable accuracy. This work presents the first comprehensive investigation integrating EFA and HSDT for sandwich plates with lattice cores, providing an analytical framework for efficient and accurate vibroacoustic analysis of these advanced composite structures.