TRANSVERSE FREE VIBRATION OF STIFFENED PLATES/SHELLS WITH ELASTICALLY RESTRAINED EDGES BY FEM

Article type: Research Article

Authors: Sinha, Gobinda

Affiliations: Indian Register of Shipping, Technical Services ivision, Research & Co-ordination Cell, Powai, Mumbai, India

Abstract: An isotropic high precision triangular stiffened shallow shell element of 36 d.o.f. are introduced to investigate the undamped free vibration behaviour of unstiffened and stiffened plates/shells supported on elastically restrained edges. In the formulation, the stiffener may take up any arbitrary orientation within the shell element, and it need not necessarily be placed along the nodal line. The consistent boundary stiffness matrix has been formulated to distribute the values of stiffness coefficients at all the nodes of the elements on elastic boundary which ensures better accuracy to obtain the natural frequencies of the stiffened structure. A number of numerical problems on stiffened and unsiffened plates/shells have been solved and the values are compared with the available theoretical results. Results show good agreement with the compared values. A new set of results on doubly curved stiffened shell with convergence study has also been presented which will be valuable to the future investigators in this field.

Journal: International Shipbuilding Progress, vol. 47, no. 450, pp. 191-214, 2000