Comprehensive Optimization Of Static Load Of Hull Girder Based On Subdivision

Ship subdivision is directly related to the static water load of the whole ship,and then affects the overall and structural design of the ship.With more and more attention paid to ship subdivision design,reducing the hydrostatic bending moment of ship girder by optimizing and improving subdivision design has become a hot topic in ship field.In the traditional subdivision process,designers usually carry out manual subdivision with experience or reference to the mother ship.This peper is based on the high-tech ship scientific research project of ministry of industry and information technology and ministry of finance <research on practical lightweight hull design technolog> According to the specification requirements of MARPOL and HCSR,this paper applies the secondary development function of NAPA to carry out subdivision optimization for oil tankers by using exhaust method and genetic algorithm.The main research work of this paper is as follows:(1)The optimization parameters and objectives for the tanker model are determined.According to the specification requirements of MARPOL and HCSR,this paper studies the subdivision layout requirements applicable to oil tanker,and determines the optimized constraint conditions,such as buoyancy,damage stability,integrity stability,assumed oil spill and accidental oil spill.(2)Based on the secondary development of NAPA,exhaustive method was adopted to write a program to automatically modify the position of the bulkhead to calculate the hydrostatic bending moment under various loading conditions.,so as to improve the efficiency of ship subdivision.The program can automatically obtain the required data for calculation,and eliminate the schemes that do not meet the requirements of floating state,complete stability,damage stability,accidental oil spill and assumed oil spill of oil tanker,etc.,which can be used in the engineering field of oil tanker cargo and oil tank subdivision.(3)Genetic algorithm was used to construct the optimization process,based on the Manager function and secondary development function in NAPA.VLCC is taken as the research object.Taking the transverse bulkhead position of the oil tanker as the optimization parameter and the hydrostatic bending moment of the ship beam as the optimization objective,the subdivision optimization of the oil tanker was carried out.(4)Camparing exhaustive method and genetic algorithm on the efficiency and effect of subdivision optimization,a better algorithm is attained.