Load Criteria for Ship Structural Design
Final technical rept.
WEBB INST OF NAVAL ARCHITECTURE GLEN COVE NY
Pagination or Media Count:
Consideration is given to the critical loads on ships hulls, as indicated by possible modes of structural damage andor failure. An ultimate load criterion is then set up involving the following bending moments quasi- static wave-induced, vertical and lateral combined, still water, including effect of ships own wave, dynamic loads, including slamming, whipping, and springing, and thermal effects. The determination of each of these loads is discussed in detail, and the need for further clarification of dynamic loads is brought out. Methods of combining these loads, all expressed in probability terms, are considered. A criterion for cyclic loading is discussed, involving the prediction of the expected number of combined loads of different levels, as well as the expected shifts of mean value. A criterion for brittle fracture is also discussed. Attention is given to estimating an acceptable probability of failure for use in design. Finally, calculations of loads are carried out for a typical cargo ship, the S.S. Wolverine State. The loads are then combined in accordance with the proposed ultimate load criterion and compared with the standards under which the ship was designed.
- Marine Engineering