Free Vibration of Functionally Graded Material Sandwich Plates with Soft Core

PurposeStudying the vibration behavior of functionally graded material (FGM) sandwich structures is crucial for their applications in aerospace and other fields. However, there is little research on the vibration behavior of functionally graded material soft core sandwich plates under different boundary conditions. The purpose of this study is to investigate the free vibration of functionally graded material sandwich plates with soft core layers under different boundary conditions, and to explore the influence of different parameter changes on the natural frequency of functionally graded material soft core sandwich plates under different boundary conditions.MethodsBased on the theory of refine shear deformation, a new free vibration model of FGM soft core sandwich plates under different boundary conditions with only four unknown variables is proposed. There are only four unknown variables for the motion equation and model. Derive the equation of motion through Hamilton's principle. Based on the motion equation, analytical solutions for FGM soft core sandwich plates under various boundary conditions are obtained. The analytical solution of free vibration of Al/Al2O3 FGM soft core sandwich plates under simply supported boundary conditions was compared with the results in the literature to verify the accuracy of the model proposed in this paper. In addition, two different shape functions were used to analyze the free vibration of FGM soft core sandwich plates under different boundary conditions.ResultsThe dimensionless natural frequencies of FGM soft core sandwich plates under different boundaries will increase with the increase of side-to-thickness ratio and volume fraction index, and decrease with the increase of aspect ratio. Moreover, the dimensionless natural frequencies of symmetric FGM soft core sandwich plates under different boundary conditions are higher than those of asymmetric FGM soft core sandwich plates under different boundary conditions.ConclusionThe changes in different parameters have different effects on the free vibration of three sets of FGM soft core sandwich plates with different material groups under different boundary conditions. However, regardless of the parameter changes, the natural frequencies of these three different material groups of FGM soft core sandwich plates are the highest under FCFC boundary conditions and the lowest under SSSS boundary conditions.