THE FLEXURAL VIBRATION OF RECTANGULAR PLATE SYSTEMS APPROACHED BY USING ARTIFICIAL SPRINGS IN THE RAYLEIGH-RITZ METHOD

A Rayleigh-Ritz approach for the study of the free vibration of systems comprised of rectangular plates is presented. The choice of the deflection functions for the component plates is simplified through the use of the concept of artificial springs being introduced at the joints between the plates and at the system boundaries; the shape functions for each component are thus those for a fully free plate. The necessary continuity and boundary conditions are enforced through allowing the appropriate spring stiffnesses to become very high compared with the stiffness of the components or, if flexible joints exist, the stiffnesses of the connecting springs are taken to be their true value. The applicability and the accuracy of the approach are illustrated through the consideration of three different types of systems: a stepped thickness plate, plates with slits (which approximate cracks) and box-type structures. © 1992.