Ultimate strength assessment of naval and commercial ships


  1. Smith, M.J.
Corporate Authors
Defence R&D Canada - Atlantic, Dartmouth NS (CAN)
The ultimate strength of several commercial and naval ship designs is studied using DRDC’s ULTMAT code. In ULTMAT, the compressive stress-strain response of local structure is predicted in a simplified manner using one of two methods: interpolation from libraries of pre-calculated load-shortening curves, or using simplified analytical formulas for the nonlinear load-shortening behaviour. The latter formulas are based on structural rules published by the International Association of Classification Societies (IACS). Load-shortening curves predicted by ULTMAT are compared with nonlinear finite element analysis (FEA) calculations for seventeen longitudinally stiffened panels and twelve transversely stiffened panels. Hull girder ultimate strength results are presented for six benchmark ship cross sections and are compared with previously published results. A further set of results for the HALIFAX class midships cross section strength is presented and is shown to agree well with the results of previous studies. The comparisons demonstrate the overall accuracy of ULTMAT’s prediction of structural strength, but reveal some deficiencies in specific areas. Using the IACS rules generally gives results of accuracy acceptable for design purposes. Interpolating curves from two of ULTMAT’s existing libraries generally gives results that are within 10% for hull girder strength. The accuracy can be improved by substituting load-shortening curves for selected panels with curves calculate

Il y a un résumé en français ici.

Report Number
DRDC-ATLANTIC-TR-2008-059 — Technical Report
Date of publication
01 Aug 2008
Number of Pages

Permanent link

Document 1 of 1

Date modified: