Study On Structural Lightweight Of Large Yacht

With the development of ship trade and maritime tourism in our country,the yacht trade develops rapidly.At present,the domestic yacht structure design and manufacture is mainly carried out according to the code method.However,the standard calculation results are relatively conservative,resulting in a large amount of material waste in the manufacturing process,while increasing the construction cost and fuel consumption.Based on this background,how to achieve ship lightweight is an urgent problem for enterprises to solve.According to the practical needs of enterprise engineering projects,this thesis takes a well-known yacht company’s 76 ft yacht as the research object,carries out standardized design,and reduces its overall quality based on the existing material characteristics and structure optimization methods,so as to realize the ship lightweight design.The main research is as follows:Firstly,the margin of boat structure optimization is discussed.In order to improve the optimization margin,the structure size is obtained by the design calculation based on the standard method.Combined with the influence of the aggregate on the strength of the yacht body,through practical construction experience and simulation analysis,the aggregate with large equivalent effect force is strengthened by carbon fiber material.And by using the finite element method analysis,the enhancement effect is obvious,and the structure optimization margin is obviously improved.Secondly,the optimization variables of yacht structure are selected.In order to improve optimization efficiency and effectively reduce optimization variables,based on the sensitivity analysis theory,the whole ship mass and structural stress level were analyzed and calculated by finite element simulation,and the variables that had a greater impact on the mass and stress were selected as the main optimization variables of the yacht body.Then the sparse grid model is considered to be effective for high dimensional problems,the adaptive sparse grid model is introduced into the yacht optimization process.The comparison with other experimental design methods shows that the adaptive sparse grid model generates fewer initial sample points,which can effectively improve the computational efficiency.The reliability of the model is tested by randomly generated sample points,and the reliability of the adaptive sparse grid model meets the requirements.Finally,the generated sparse grid model was combined with the Multi-objective genetic algorithm to minimize the quality as the optimization goal,the iterative solution of the structural optimization model was carried out,and a group of optimal schemes were obtained,and the structural strength after optimization met the design requirements.Compared with before optimization,the whole ship mass is reduced by 10.8%,the optimization effect is remarkable,and the purpose of lightweight research is realized.The key points of VARI are pointed out and used in the molding process of the yacht body to realize the effective play of the properties of fiber reinforced materials,and provide reference value for improving the molding process of this type of yacht body.