Differential Quadrature Free Vibration Analysis of Sandwich Plates with Curvilinear Fiber Variable Stiffness Composite Face Sheets

Free vibration calculations of Sandwich plates with curvilinear fiber variable stiffness composite face sheets usually require a significant computing effort to obtain a high computational accu-racy. In order to get the natural frequencies of sandwich plates with high computational accuracy and low computational cost, an improved approach integrating the differential quadrature method (DQM) and first-order shear deformation theory (FSDT) is introduced in this work. The skins of sandwich plates are composed of one or several layers of variable stiffness composite laminates (VSCL) with fiber paths assumed to follow a specific linear pattern. The FSDT and von Kármán strain–displacement relationship were used to derive the governing equations of the sandwich plate, and DQM was applied to discretize such governing equations and solve for the fundamental frequency of the sandwich plate. The computational results were verified and compared with other FSDT–based computational results, and there was good agreement with the suggested model. Also, the variation patterns of the natural frequency under different pa-rameters such as fiber orientation angles, boundary conditions, number of layers, and core/skin thickness were investigated. This study entailed the development of an efficient solution to the problem of the fundamental frequency of VSCL sandwich plates, and the outcomes could pro-vide a basis for future dynamics comparative studies.