SPRINGING AND HYDROELASTIC PROBLEMS OF LARGE SHIPS
The increasing size of ocean-going cargo ships has resulted in their experiencing the phenomenon of wave-excited hull vibration or "springing," a hydroelastic problem that was once confined almost exclusively to Great Lakes ore carriers. The problem is identified as being primarily one of fundamental hull frequency matching the encounter frequency of waves possessing sufficient energy for hull excitation. Assuming that synchronous wave encounter is the primary source of springing excitation, the major problem then becomes one of predicting the magnitude of the exciting forces, calculating the structural response, and determining the significance of the results in terms of ship-design criteria. This paper concentrates on the relative importance of the various components of the springing excitation and response forces and concludes that of most significance in determining the trends of springing response is the distribution of the various forces at the ends of the ship. Also, it is at the end of the ship that the greatest uncertainty exists in the calculation of hydrodynamic mass and damping values. It is shown that buoyancy forces are important in the excitation as well as the response, and that the most difficult problems to handle analytically are those of frequency-dependent hydrodynamic coefficients and non-proportional damping.
- Presented at the First Ship Technology and Research (STAR) Symposium, Washington, D.C., August 26-29, 1975.
Society of Naval Architects and Marine Engineers601 Pavonia Avenue
Jersey City, NJ United States 07306-2907
- Kline, R G
- Publication Date: 1975-8
- Features: References;
- Pagination: 10 p.
- TRT Terms: Hulls; Measurement; Vibration
- Old TRIS Terms: Hull vibration; Springing; Vibration measurement
- Subject Areas: Marine Transportation; Materials;
- Accession Number: 00126929
- Record Type: Publication
- Source Agency: Society of Naval Architects and Marine Engineers
- Report/Paper Numbers: #1
- Files: TRIS
- Created Date: Nov 5 1975 12:00AM