Vibration Analysis of Sandwich Plates with Hybrid Composite Cores Combining Porous Polymer and Foam Structures

Sandwich structures are composites comprising a core layer sandwiched between two face layers; each layer has a distinctive characteristic, and the structure can also include composite layers. This study presents an investigation of the free vibration behavior of a cored hybrid sandwich plate. The research demonstrates an analytical and numerical analysis. Sandwich plate models made of aluminum face sheets with reinforced cores are used in this study. The analytical analysis used in this study of a three-layer sandwich plate is based on Kirchhoff's theorem. An additional mathematical model is constructed by dividing the core layer into two parts to form four layers with a hybrid structure. The governing equations to obtain the mechanical properties and natural frequency of the foam composite, as well as open structural and hybrid cores, were used in this study. The numerical analysis of the various composite structures using the modal analysis was performed through ANSYS version 2021-R1. Analytical outcomes reveal that replacing the foam core with an open-cell structure reduces the natural frequency by 25%. However, the hybrid core structure reduces the natural frequency by 27.6%. Also, the ultimate flexural load in the hybrid structure is increased by 127.7% compared to the open-cell structure core. Finally, numerical results are highly consistent with those obtained analytically.