Free vibration characteristics of honeycomb sandwich cylindrical shells reinforced with graphene nanoplatelets/polymer coatings

This study conducts a comprehensive analysis of the free vibration characteristics of honeycomb sandwich cylindrical shells reinforced with graphene nanoplatelets (GNPs). The shells are modeled with a hexagonal honeycomb core, which not only provides a lightweight structure but also enhances the stiffness and dynamic stability. This core design is ideal for high-performance applications such as aerospace and light transport equipment. In addition, the incorporation of graphene nanoplatelet/polymer coatings further improves the structural stiffness, making these shells suitable for demanding environments where both strength and lightweight properties are critical. In the theoretical model, the refined trigonometric shear deformation theory (RTSDT) is applied to accurately represent both bending and shear deformations, capturing the complex behavior of honeycomb sandwich cylindrical shells without requiring shear correction factors. Various parameters, including axial and circumferential wave numbers, as well as geometry and material properties, are examined to assess their impact on natural frequencies. Comparisons with existing literature validate the theoretical models, demonstrating strong agreement with previous results. The analysis reveals that the fundamental natural frequency and other natural frequencies are significantly affected by the inclusion of GNPs and variations in sandwich cylindrical shell geometry. The findings underscore the effectiveness of the RTSDT in modeling these complex sandwich structures.