REDUCTION OF WHIPPING STRESSES IN WARSHIPS: AN EXPLORATORY MODEL TEST

PDF

Authors
  1. Ando, S.
  2. Hermanski, G.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN)
Abstract
An exploratory towing-tank test with a segmented structural model of the Halifax-class frigate was conducted to investigate the concept of reducing the slam-induced hydroelastic shocks by an elastomer bonded to the exterior of the ship's bottom forward. We afixed a 6.35-mm thick sheet of elastomer (closed cellular rubber) to the forward 1/4 ship length of hull bottom from the keel up to 33 percent of draft. We found a 15-percent reduction, in terms of zero-crossing peak-to-trough values, in the magnitude of the most severe slam-induced vertical bending moment amidships at model speed corresponding to 20 knots full scale in sea state 7. Reductions were also realized for bow acceleration, shear forces, and pitch angles. The results showed that the severer the sea state, the greater the cushioning effect. Further model tests are needed to categorically establish the relative influence of three types of impact on whipping stresses for Halifax-class frigates: bow-bottom slamming, bow-flare impact, and green seas on the fore deck.
Date of publication
30 Mar 1997
Number of Pages
10
DSTKIM No
97-00717
CANDIS No
501058
Format(s):
Hardcopy;Document Image stored on Optical Disk

Permanent link

Document 1 of 1

Date modified: