Computational & Technology Resources
an online resource for computational,
engineering & technology publications
Civil-Comp Proceedings
ISSN 1759-3433
CCP: 81
PROCEEDINGS OF THE TENTH INTERNATIONAL CONFERENCE ON CIVIL, STRUCTURAL AND ENVIRONMENTAL ENGINEERING COMPUTING
Edited by: B.H.V. Topping
Paper 230

The Longitudinal Strength and Vibration of Model Ships

C.T.F. Ross and E. James

Department of Mechanical Engineering, University of Portsmouth, United Kingdom

Full Bibliographic Reference for this paper
C.T.F. Ross, E. James, "The Longitudinal Strength and Vibration of Model Ships", in B.H.V. Topping, (Editor), "Proceedings of the Tenth International Conference on Civil, Structural and Environmental Engineering Computing", Civil-Comp Press, Stirlingshire, UK, Paper 230, 2005. doi:10.4203/ccp.81.230
Keywords: longitudinal strength, vibration, ships, finite element method, ANSYS.

Summary
The paper reports on a theoretical and an experimental investigation into the longitudinal strength and vibration of 6 model ship structures. The theoretical studies were via the Finite Element method, where the computer package ANSYS was used.

Two of the model ships had two superstructures, while two had one superstructure. The remaining two model ships had no superstructures.

Part of the study was to check the validity of using Finite Element methods for such structures and part of the study was to determine the effect of superstructures on model ships.

The study showed that the Finite Element method was most suitable for the analyses of such structures. It also showed that superstructures do strengthen ships, but do not change their resonant frequencies appreciably.

The longitudinal strength and vibration of ships is of much importance in marine studies and many studies have been made on them [1,2,3,4,5,6,7] over a number of years.

In this paper, a theoretical and an experimental study has been made on the effect of superstructures on the longitudinal strength and vibration of 6 ship models. The models are shown in Figure 230.1, where it can be seen that there are two families of models. Models 2, 3 & 4 had 3 decks. Models 1, 5 & 6 had 2 decks. Models 3 & 6 had no superstructures. Models 1 & 5 had one superstructure. Models 2 & 4 had two superstructures. The superstructures on Models 4 & 5 had sloping transverse and longitudinal external bulkheads. The superstructures on Models 1 & 2 had vertical external bulkheads.

It should be emphasized that the adoption of external sloping bulkheads is popular with modern day warships as they help such vessels to be less vulnerable to missile attack. All 6 models were constructed in Polymethyl Methacrylate. (PMMA or 'Perspex').

Figure 230.1: Ship Models 1 to 6.
Model 1: Single superstructure Model 2: Double superstructure
Model 3: No superstructure Model 4: double, inclined superstructure
Model 5: Single, inclined superstructure Model 6: No superstructure

References
1
Muckle, W., Strength of Ships Structures, Edward Arnold Ltd., London, 1967.
2
Muckle, W., The Design of Aluminum Alloy Ships Structures, Hutchinson, London,1963.
3
Rossell, H.E. and Chapman, L.B., Principles of Naval Architecture, Vols. 1 & 2, SNAME, Jersey City, USA, 1958.
4
Mackney, M.D.A. and Ross, Carl T.F., Superstructures Effectiveness in the Preliminary Assessment of the Hull Behavior, SNAME, J. Marine Technology, 36, 1, 1999.
5
Mackney, M.D.A. and Ross, Carl T.F., Preliminary Ship Design using One-and-Two-Dimensional Models, SNAME, J. Marine Technology, 36, 2, 1999
6
Smith, C.S. and Chalmers, D.W., Design of Ships Structures in Fibre-Reinforced Plastic, Trans. RINA, May 1987, pp. 45-62.
7
Brown, D.K., Naval Architecture, Naval Engineers Journal, Jan. 1993. doi:10.1111/j.1559-3584.1993.tb02705.x

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £135 +P&P)