A theoretical approach to the optimization of flexural stiffness of symmetric laminates

A theoretical study is performed to optimize the design of symmetrically laminated plates with respect to fiber orientation and layer thickness. Rectangular plates simply supported along the edges and with transverse pressure load are considered. The expression for plate flexural stiffness is obtained using approximate energy approaches, such as Ritz-Rayleigh method, using different shape functions. Results of analytical solution are compared with results from finite element analysis, which show a good correlation between theoretical and numerical results. Optimality criteria are applied to the analytical expression of flexural stiffness to determine the optimality condition. A closed form solution is obtained for the fiber orientation and it is demonstrated that the optimal orientation of the fiber is unique and independent of the stacking sequence. Results are also obtained for the optimal values of thickness for each layer. \ua9 1995