In this article, the nonlinear equations of motion for anti-symmetric angle-ply composite rectangular plates have been derived using the first-order shear deformation theory, including shear deformation and rotary inertia. By using the Galerkin method, five coupled nonlinear partial differential equations of motion are reduced to a nonlinear ordinary differential equation. Then, the multiple time scales method is used to solve the obtained equation and to derive an analytical relation for the nonlinear frequency. Results are compared with the literature and good agreement is achieved. After proving the validity of this study, nonlinear free and forced vibration of a fiber metal laminated rectangular plate have been studied and the effects of some system parameters on the nonlinear behavior of the FML rectangular plate have been investigated.
