AN INVESTIGATION ON FUNDAMENTAL FREQUENCIES OF LAMINATED CIRCULAR CYLINDERS GIVEN BY SHEAR DEFORMABLE FINITE ELEMENTS
✍ Scribed by G. Sun; P.N. Bennett; F.W. Williams
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 180 KB
- Volume
- 205
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
The fundamental frequencies of laminated anisotropic circular cylindrical composite shells are investigated by using nine-noded isoparametric quadratic finite elements based on extended Sanders' first order shear deformable shell theory. Finite element (FE) results are presented for cylinders and compared with the exact results obtained by a computer program written by the authors and using the same shear deformable theory. Such comparisons are important to validate the FE method, because exact results can be obtained for only a few special lamination and boundary cases, and cannot be applied to cylinders with non-uniform structural or loading characteristics, holes, etc. In addition, results are compared with shear deformable results obtained by using numerous flat strips and the exact flat strip program VICONOPT. The agreement of the finite element results with the exact results is found to be good, including degenerated cases in which the shear stiffness approaches infinity: i.e., classical results. The effects of boundary conditions and lamination schemes on the fundamental frequency are also investigated. It is found that cylinders require many more elements than might be predicted from open shell panels in order to obtain any specified accuracy.