International Journal of Naval Architecture and Ocean Engineering

The Society of Naval Architects of Korea (대한조선학회)
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Extraction of the mode shapes of a segmented ship model with a hydroelastic response

  • Kim, Yooil (Department of Naval Architecture and Ocean Engineering, Inha University) ;
  • Ahn, In-Gyu (Department of Naval Architecture and Ocean Engineering, Inha University) ;
  • Park, Sung-Gun (DSME R&D Institute, Daewoo Shipbuilding and Marine Engineering Co., Ltd.)
  • Received : 2015.05.29
  • Accepted : 2015.08.03
  • Published : 2015.11.30
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Abstract

The mode shapes of a segmented hull model towed in a model basin were predicted using both the Proper Orthogonal Decomposition (POD) and cross random decrement technique. The proper orthogonal decomposition, which is also known as Karhunen-Loeve decomposition, is an emerging technology as a useful signal processing technique in structural dynamics. The technique is based on the fact that the eigenvectors of a spatial coherence matrix become the mode shapes of the system under free and randomly excited forced vibration conditions. Taking advantage of the simplicity of POD, efforts have been made to reveal the mode shapes of vibrating flexible hull under random wave excitation. First, the segmented hull model of a 400 K ore carrier with 3 flexible connections was towed in a model basin under different sea states and the time histories of the vertical bending moment at three different locations were measured. The measured response time histories were processed using the proper orthogonal decomposition, eventually to obtain both the first and second vertical vibration modes of the flexible hull. A comparison of the obtained mode shapes with those obtained using the cross random decrement technique showed excellent correspondence between the two results.

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References

  1. Cole, H.A., 1968. On-the-line analysis of random vibrations. AIAA Paper 68-288, 9th Structures, Structural Dynamics and Materials Conference, Palm Springs, California.
  2. Cole, H.A., 1971. Method and apparatus for measuring the damping characteristics of a structure. United States Patent No.3, 620,069.
  3. DNV, 2000. Environmental conditions and environmental loads, Classification Notes No.30.5. Norway: DNV.
  4. Drummen, I., Wu, M.K. and Moan, T., 2009.Experimental and numerical studyof containership responses in severe head seas. Marine Structures, 22(2), pp.172-193. https://doi.org/10.1016/j.marstruc.2008.08.003
  5. Feeny, B.F. and Kappagantu, R., 1998. On the physical interpretation of proper orthogonal modes in vibrations. Journal of Sound and Vibration, 211, pp.607-616. https://doi.org/10.1006/jsvi.1997.1386
  6. Feeny, B.F., 2002. On proper orthogonal coordinates as indicators of modal activity. Journal of Sound and Vibration, 255, pp.805-817. https://doi.org/10.1006/jsvi.2001.4120
  7. Hirdaris, S.E., Bakkers, N., White, N. and Temarel, P., 2009. Service factor assessment of a great lakes bulk carrier incorporating the effects of hydroelasticity. Marine Technology, 46(2), pp.116-121.
  8. Hirdaris, S.E., Price, W.G. and Temarel, P., 2003. Two-and three-dimensional hydroelastic analysis of a bulker in waves. Marine Structures Special issue on Bulk Carriers, 16, pp.627-658.
  9. Hong, S., Kim, B.W. and Nam, B.W., 2011. Experimental study on torsion springing and whipping of a large container ship. In: Proceedings of the 21st International Offshore and Polar Engineering Conference, Maui, Hawaii, USA, June 2011.
  10. Ibrahim, S.R. and Mikulcik, E.C., 1977. A method for the direct identification of vibration parameter from the free response. Shock and Vibration Bulletin, 47(4), pp.183-198.
  11. Iijima, K, Hermundstad, O.A., Zhu, S. and Moan, T., 2009. Symmetric and antisymmetric vibrations of a hydroelastically scaled model. In: Proceedings of the 5th International Conference on Hydroelasticity in Marine Technology, Southampton, UK, September 2009.
  12. Jensen, J.J. and Dogliani, M., 1996. Wave-induced ship hull vibrations in stochastic seaways. Marine Structures, 9, pp.353-387. https://doi.org/10.1016/0951-8339(95)00031-3
  13. Jensen, J.J., 2009. Stochastic procedures for extreme wave load predictions-wave bending moment in ships. Marine Structures, 22(2), pp.194-208. https://doi.org/10.1016/j.marstruc.2008.08.001
  14. Kim, K.H., Bang, J.S., Kim J.H., Kim, Y., Kim, S.J. and Kim, Y., 2013. Fully coupled BEM-FEM analysis for ship hydroelasticity in waves. Marine Structures, 33, pp.71-99. https://doi.org/10.1016/j.marstruc.2013.04.004
  15. Kim, Y. and Park, S.G., 2013. Wet damping estimation of the segmented hull model using the random decrement technique. Journal of the Society of Naval Architects of Korea, 50(4), pp.217-223. https://doi.org/10.3744/SNAK.2013.50.4.217
  16. Kim, Y., 2009. Time domain analysis on hull-girder hydroelasticity by fully coupled BEM-FEM Approach. PhD Thesis. Seoul National University.
  17. Lumley, 1970. Stochastic tools in turbulence. New York: Academic Press.
  18. Malenica, S., Molin, B. and Senjanovic, I., 2003. Hydroelastic response of a barge to impulsive and non-impulsive wave loads. In: Proceedings of the 3rd International Conference on Hydroelasticity in Marine Technology, Oxford, UK, September 2003.
  19. Malenica, S., Senjanovic, I. and Vladimir, N., 2013. Hydro structural issues in the design of ultra large container ships. Brodogradnja, 64(3), pp.323-347.
  20. Mariani, R. and Dessi, D., 2012. Analysis of the global bending modes of a floating structure using the proper orthogonal decomposition. Journal of Fluids and Structures, 28, pp.115-134. https://doi.org/10.1016/j.jfluidstructs.2011.11.009
  21. Miyake, R., Matsumoto, T., Yamamoto, N. and Toyoda, K., 2010. On the estimation of hydroelastic response acting on an ultra-large container ship. In: Proceedings of the 20th International Offshore and Polar Engineering Conference, Beijing, China, September 2010.
  22. Miyake, R., Matsumoto, T., Zhu, T., Usami, A. and Dobashi, H., 2009. Experimental studies on the hydroelastic response using a flexible mega-container ship model. In: Proceedings of the 5th International Conference on Hydroelasticity in Marine Technology, Southampton, UK, September 2009.
  23. Oka, M., Oka, S. and Ogawa, Y., 2009. An experimental study on wave loads of a large container ship and its hydroelastic vibration. In: Proceedings of the 5th International Conference on Hydroelasticity in Marine Technology, Southampton, UK, September 2009.
  24. Price, W.G. and Temarel, P., 1982. The influence of hull flexibility in the anti-symmetric dynamic behavior of ships in waves. International Shipbuilding Progress, 29.
  25. Remy, F., Molin, B. and Ledoux, A., 2006. Experimental and numerical study of the wave response of a flexible barge. In: Proceedings of the 4th International Conference on Hydroelasticity in Marine Technology, Wuxi, China, September 2006.
  26. Senjanovic, I., Vladimir, N., Tomic, M., Hadzic, N. and Malenica, S., 2014. Global hydroelastic analysis of ultra large container ships by improved beam structural model. International Journal of Naval Architecture and Ocean Engineering, 6(4), pp.1041-1063. https://doi.org/10.2478/IJNAOE-2013-0230
  27. Wu, M.K. and Moan, T., 1996. Linear and nonlinear hydroelastic analysis of high-speed vessel. Journal of Ship Research, 40(2), pp.149-163.

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