Evaluation Of Strength For Double Hull Structure And Optimization Of Hull Weight

For bulk carriers, the side shell is one of the weakest parts of the hull. Most ofprevious bulk carriers are single-hull bulk carriers, according to the casualty statisticsof bulk carriers, the accident rate of the side shell of the single-hull bulk carriers ishighest among hatch, pipe, deck, side shell and bottom etc. In order to solve theseproblems which appear in hull structure and the process of managing, and improve thesecurity of bulk carriers especially the senile bulk carriers, the double-hull structure ofbulk carriers is put to the schedule of IMO increasingly. An example of a bulk carrieris given in this article, the shear stress of single-hull and double-hull structure iscalculated respectively using the method of shear flow. The result indicates that theshear stresses of side shell, top and hopper tank are decreased a lot by introducing thedouble-hull structure, while the changes of shear stresses in other parts are decreasedlittle.Many advantages are brought for the structure strength, use and maintenance byintroducing the double-hull structure, but the structure weight is increased and thevolume of the cargo hold is decreased at the same time. In order to solve this problem,the optimum structural design of double hull bulk carriers becomes necessary. In thisarticle, the longitudinal, the transverse and transverse bulkhead members areoptimized individually using the Evolutionary Computation. The result indicates thatthe weight of the double hull bulk carrier can be reduced to a reasonable amount incomparison with the existing single hull types, not optimized.