Dispersion and damping analysis of orthotropic composite plate in mid frequency based on symplectic method

A semi-analytical method is used to investigate the dispersion and damping characteristics for rectangular thin orthotropic composite plates in mid frequency analysis. A symplectic eigenproblem is formed whose solution gives analytically the dispersion equation and the wave shape for any combination of simple boundary conditions along the plate edges. The damping capacity of each wave component is obtained using the strain energy theory. In the numerical examples, the dispersion and damping characteristics are calculated and analyzed for orthotropic composite laminated plates with three different combinations of boundary conditions. Comparison of the present results with the Rayleigh-Ritz results and the finite element results validates the effectiveness of the present method. Based on the damping analysis in the wave domain, the thresholds of mid frequency and high frequency vibration characteristics of the composite plate are illustrated. The relationship between the wave components in the present method and the modal modes in the modal method is also explained.