INVESTIGATION OF WATER IMPACT OF BLUNT BODIES

The report summarizes results of an experimental study to determine the influence of hull form, water surface state, and elasticity of a model bottom on the peak pressures experienced by a body impacting on a water surface. Three two-dimensional models were constructed having section shapes of a U, UV, and V form, but identical extent of flat bottom. Drop tests were performed on still water and on waves, and impact pressure data was obtained at several locations on the bottom of each model. For impacts on still water, the peak pressure varies in a complex fashion as a function of basic shape, mass loading, and extent of flat bottom. For impacts on waves, the pressure values are quite random for subsequent drops, and the average value for a large number of samples is greatly reduced from the still water pressure value. It is concluded that the impact machanism for waves is quite different from the still water impact condition, and the wave data correlates well with model seaworthiness test results. The effect of bottom elasticity is observed with regard to the peak impact pressure. Work hardening of the elastic bottom is related to the cushioning effect, in which the peak pressure increases for subsequent drops. (Author)

• Corporate Authors:

  Southwest Research Institute

  Department of Mechanical Sciences
  San Antonio, TX  United States  78284
• Authors:
  • Gerlach, C R
  • Astleford, W J
• Publication Date: 1970-12

Media Info

• Pagination: 87 p.

Subject/Index Terms

• TRT Terms: Drop tests; Hulls; Impact; Pressure; Slamming
• Old TRIS Terms: Hull forms; Impact pressure
• Subject Areas: Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00019455
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: Final Rpt
• Contract Numbers: N00014-67-C-0213
• Files: TRIS
• Created Date: Nov 19 1972 12:00AM