Dynamic characteristics of composite laminates

An exact solution for the vibration of elastic composite laminates in cylindrical bending is presented. Dispersion curves for multi-layer symmetrical and unsymmetrical laminates with materials possessing high and low degrees of anisotropy at various fiber orientations are compared with those obtained from an approximate shear deformation theory. Mode shapes are also drawn for different wavelengths and their variation with fiber orientation is studied. Equations are developed for the wave propagation in an infinite medium consisting of a repeated pair of anisotropic layers by extending the “continuum” theory of Sun, Achenbach and Herrmann. Dispersion characteristics for 0–90° fiber orientations obtained by the “continuum” approach are also compared with those obtained by the exact method. The range of validity of each approximate theory is then assessed.