For a large quantity of variables and low efficiency problems in ship structural optimization, based on the particle swarm optimization (PSO), a structural optimization method for deck grillage of large oil tanker is carried out. The mid-section of an 8,0000 tons tanker is taken as an example, while the minimum cross-sectional area taken as the design target and the dimensions of the structural members in sides and bottom taken as constants, the original dimensions and arrangements parameters of the ship to be optimized are regarded as the initial values in PSO. According to the related descriptive requirements of the common structural rules for bulk carriers and oil tankers (HCSR), PSO is innovatively integrated into the optimization process of the target ship deck structure through the self-programming program, where the specifications of common shipbuilding plating and stiffeners are proposed as the alternative material library. Compared to the original structures, the weight of the ship decreases 2.81% by using the optimal design method based on PSO presented in this study, which further proves that the proposed structural optimization method for deck grillage of large oil tanker based on PSO is effective to deck grillage's structural optimization combined with finite element analysis.
Common Structural Rules for Bulk Carriers and Oil Tankers (CSR) (IACS, 2006) are divided into two parts: the Common Structural Rules for Bulk Carriers (CSR-BC) and the Common Structural Rules for Oil Tankers (CSR-OT), which are compiled by different members of the International Association of Classification Societies (IACS). As a result, the different technical routes and technological backgrounds of the two parts lead to uncoordinated problems in commonness (Gang and Daokun, 2011). In order to harmonize the two parts and eliminate these unnecessary differences, on July 1, 2012, the first draft of HCSR was promulgated (IACS, 2015) and the self-trial in each classification society was completed in 2013. On July 1, 2015, HCSR formally came into force.