DYNAMIC ANALYSIS INVESTIGATION OF STIFFENED AND UN-STIFFENED COMPOSITE LAMINATED PLATE SUBJECTED TO TRANSIENT LOADING

A suggested analytical solution for static and dynamic analysis of stiffened and un stiffened composite plates is presented using the general Third-order Laminated plate theory that contains Classical, First order, and third-order theories as special cases. The general Third-order theory of Reddy and the higher order shear deformation theory of Reddy are also presented. The Navier solutions is limited to simply supported rectangular plates using static analysis. The dynamic analysis for equations of motion, for those theories are presented, solved by using the modal analysis of forced vibration. The results are the response ,stresses, and inter-laminar shear stresses, solution by first order shear deformation theory "FSDT", for symmetric and antisymmetric, cross-ply and angle-ply, laminated plates subjected to the static and dynamic loading conditions considered here is the sine, rectangular, expanison, ramp and triangular pulses while spatially, they are considered as central sinusoidal and uniformly distributed load for stiffened and unstiffened laminated plates. In addition, the results for deflections, stresses and inter-laminar shear stresses are presented showing the effect of plate side-to-thickness ratio, aspect ratio, material orthotropy, fiber orientation, boundary conditions and lamination scheme and are confirmed with other solutions and finite element results. The analysis results for deflection, stresses and inter-laminar shear stresses of stiffened laminated plates are presented showing the effect of number of stiffeners, high to width of stiffener ratio, high of stiffener, the width of stiffener, and the stiffener properties and are confirmed with other solutions and finite element results. The results obtained are the deflection, stresses, and inter-laminar shear stresses of un-stiffened plates are decreases with increasing the number of layer, fiber orientation (optimum angle 45), or thickness of laminated plates. In addition the deflection, stresses, and inter-laminar shear stresses for stiffened laminated plates are decreases with increasing the number of stiffeners, thickness, or height of stiffeners.