Free vibration analysis of corrugated-face sheet composite sandwich plates

Free vibrational characteristics of corrugated sandwich plates consisting of two corrugated composite face sheets and a foam filling core were investigated. Natural frequencies of sandwich plates with sinusoidal and trapezoidal corrugation shapes are obtained and compared with that of flat sandwich plates. Three-dimensional (3D) finite element method (FEM) is employed to compare and contrast the natural frequencies. FEM models of the proposed sandwich plates are constructed using ANSYS 12.0 code. The core of the sandwich plates is assumed to be a soft isotropic material which is adhesively bonded to two stiff laminated composite face sheets. The effects of significant parameters such as corrugation shape, boundary conditions, composite layup and thickness ratio of the structure on the natural frequencies and mode shapes of the corrugated sandwich structures are assessed. Comparison of the obtained numerical results with those values available in the literatures demonstrates the accuracy of the proposed models. The numerical results indicate that employing corrugated composite face sheets increase the natural frequencies of sandwich plates, significantly.