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Advances in Fuzzy Systems
Volume 2011 (2011), Article ID 879049, 9 pages
Research Article

Optimal Fuzzy and Dynamics Design of Ecological Sandwich Panel Vessel Roofs

1Himtech Oy, Ollintie 4, 54100 Joutseno, Finland
2Oy Scanfibre Ltd., Liisankatu 26, 55100 Imatra, Finland

Received 16 December 2010; Accepted 27 July 2011

Academic Editor: Kemal Kilic

Copyright © 2011 Heikki Martikka and Erkki Taitokari. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In this study the basic engineering principles, goals, and constraints are all combined with fuzzy methodology and applied to optimally design sandwich panel circular plate roofs for large vessels loaded statically and dynamically. These panels are made up of two stiff, strong veneer skins separated by vertical and peripheral stiffener plates. Advantages are high strength, lightweight, and sustainability. In the present approach, first the goals and constraints of the end user are identified and expressed as decision variables which are formulated using the engineering variables for materials, geometry, and function. Then same consistent fuzzy satisfaction functions are formed over the desired ranges to suit the customer's desires. The risk of extreme dynamic loadings exciting resonance is studied by natural frequency and mode analysis by FEM and analytical models. The results show the most critical locations and give guidelines for innovative remedies of the concept before detailed FEM analyses to finalize the design.