SUMMARY OF INVESTIGATION OF MIDSHIP BENDING MOMENTS EXPERIENCED BY MODELS IN EXTREME REGULAR WAVES

This report summarizes experimental research to investigate the possibility of a physical upper limit on midship bending moments being reached in regular waves of height sig- nificantly less than the theoretical upper limit of progressive waves (h/lambda equals 1/7). The experiments included variation of ship type, of dis- tribution of loading and of freeboard as model parameters. The ship types investigated were a modern cargo vessel, a large tanker, and a modern destroyer. Each model was tested at various speeds in regular head and following waves of several different lengths and of a wide range of heights. No significant upper limit of bending moment was found. However, the study establishes more firmly the grossly linear dependence of midship bending moment on wave height, even for extreme wave heights which may be encountered in service. These findings strengthened the case for deter- mining design wave bending moments on the basis of statistical analyses of ocean waves and/or resulting bending moments.

• Supplemental Notes:
  • Project name is Model in Extreme Waves
• Corporate Authors:

  Ship Structure Committee

  National Academy of Science, 2101 Constitution Avenue, NW
  Washington, DC  United States  20418

  Bureau of Ships

  Washington, DC  United States 
• Authors:
  • Dalzell, J F
• Publication Date: 1963-12-18

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: 16 p.

Subject/Index Terms

• TRT Terms: Bending stress; Flexural strength; Ships; Waves
• Old TRIS Terms: Regular waves
• Subject Areas: Marine Transportation; Materials; Vehicles and Equipment;

Filing Info

• Accession Number: 00007506
• Record Type: Publication
• Report/Paper Numbers: SSC-157 Final Rpt.
• Contract Numbers: NObs-88509
• Files: TRIS
• Created Date: Dec 22 1974 12:00AM