Abstract:Free vibration of double curvature honeycomb sandwich thin shell having simple support boundary conditions was investigated by using the Reddy’s third-order theory and the influence of the structure parameter on the natural frequencies was also studied. In this study, the honeycomb core of hexagonal cells is modeled as a layer of orthotropic material whose physical and mechanical properties are determined by using the corrected Gibson’s formula. The frequency equation of the honeycomb sandwich thin shell was obtained by the Reddy’s third-order theory and the Hamilton’s law of variation principle. The results indicate that the Reddy’s third-order theory has adequate accuracy on studying the free vibration of double curvature honeycomb sandwich thin shell. The effects of the curvature, the thickness ratio and the cell angle on free vibration of double curvature honeycomb sandwich thin shell are different. The natural frequencies of honeycomb sandwich thin shell increases with the increase of the curvature, fluctuates with the increase of thickness ratio and decreases with the cell angle increasing.