Existing and conceptual ship-grillage stiffener optimization through maximizing overload capacity under transverse loads

Abstract

The HMCS IROQUOIS naval destroyer was decommissioned in 2015. Six ship hull sections have been sent to Memorial University of Newfoundland for detailed structural analyses. An investigation has been undertaken to determine if significant improvements could be made to the IROQUOIS grillage panels. If significant improvements were possible it was important to determine how the grillage could then be optimized. The study focused on grillage stiffener design. Numerous stiffener designs were tested by varying factors related to their geometric and parametrized dimensions. Both finite element analysis and experimental design techniques were implemented within the study. The statistical significance of the studied factors was analyzed to develop more detailed and specific, experiments. Control runs were tested which consisted of built-T and flat bar stiffened panels, as well as the IROQUOIS grillage panels. An optimized concept grillage was produced which demonstrated an ability to outperform the control runs.