Vibration and stability of laminated composite orthogrid plates

Abstract

Generally, a grid layer is used as an orthotropic layer to reinforce plates and shells or as an independent structural element. The proposed laminated grid plate is composed of different grid layers with different orientations. Consequently, the grid layers with different fibers, patterns and orientations can be used, resulting in laminates with enhanced stiffness and coupling effects. In the present study, to investigate the efficiency of the laminated grids, the vibration and buckling responses of a conventional and laminated grid plates are compared. The first-order shear deformation plate theory along with Ritz method is used to obtain the buckling load and natural frequencies of the plates. The effectiveness of increasing the number of layers on mechanical responses of the laminated grids is also studied. The analytical results of vibration frequencies are compared and validated by finite element method and experimental analysis of two manufactured grid plates. The results indicate that thoughtful selection of stacking sequences of the laminated grids considerably enhances the response of the laminated grids in comparison with conventional grids.