NATURAL FREQUENCIES AND MODES OF A CIRCULAR PLATE WELDED TO A CIRCULAR CYLINDRICAL-SHELL AT ARBITRARY AXIAL POSITIONS

The modal characteristics of a plate-shell coupled structure consisting of a simply supported thin circular cylindrical shell and a circular plate which may be joined to the shell at any arbitrary axial position were studied using the receptance method. Line receptances were formulated from the responses of the plate and the shell to line force and line moment loadings distributed harmonically along the interface of the plate and the shell, utilizing natural modes and frequencies of the plate and shell, respectively. The system frequency equation was generated and solved numerically to obtain the natural frequencies and mode shapes of the combined structure under different joining configurations. The effects of length, thicknesses and joining positions on the modal characteristics of the combined structure were investigated. Certain results obtained from the receptance method and a finite element program were compared for verification purposes and showed good agreement. The structural coupling behavior between the plate and the shell and the coupling relationship between the line force loading and the line moment loading were explored. © 1993 Academic Press Limited.