Nonlinear Free Vibration Analysis of a Stiffened Plate Backed by a Cavity

Free vibration analysis of an orthotropic plate backed by a closed air cavity has analytically been studied in this paper. A plate reinforced by a set of equidistant stiffeners has been modelled as an orthotropic plate. Von-Karman theory and Galerkin method are applied to derive equation of motion for the system. Harmonic balance method is employed to derive nonlinear natural frequencies of the plate-cavity system. Finally, a parametric study is carried out and effect of different parameters on the nonlinear natural frequencies have been investigated. It has been shown that an increase in number of stiffeners results in an increase in nonlinear natural frequencies of the system.