Edge Vibrations in Laminated Composite Plates

Plane strain edge vibrations or end modes in laminated composite plates are investigated by means of finite elements. This method is capable of modeling the behavior of any laminate construction whose properties are completely anisotropic within the plane. Two eigenvalue problems involving nonsymmetric matrices are derived. The form of each eigenvalue problem depends on the parameter chosen for the eigenvalue, i.e., either the frequency or the axial wave number. Orthogonality relations are discussed. Examples on two four-ply composite plates are given as illustrations. The analogy of the analysis procedure as the dynamic counterpart of the quantitative measure of Saint-Venant’s principle is called to attention.