Response And Optimization Analysis Of SPS Hull Structure Under Collision Load

With the continuous development of the marine transportation industry,the density of maritime navigation is increasing while ship collision accidents occur more frequently.Serious ship collision accidents often cause huge economic losses and casualties.Therefore,improving the crashworthiness of hull structure has become an important and active research topic in the design of modern hull structure.SPS(Sandwich Plate System)structure,as a marine sandwich plate with excellent impact resistance,is introduced into the field of hull design to improve the crashworthiness of the ship.Taking SPS structure as the research object,the crashworthiness optimization methods of ship structure are introduced firstly.Then the impact test of SPS structure is carried out to analyze the dynamic response of SPS structure under collision load and the finite element software ANSYS/LS-DYNA is utilized to analyze the crashworthiness indexes of SPS structure.In the end,the parametric analysis and crashworthiness optimization of SPS structure are carried out,and the optimized size parameters of SPS structure are obtained through the optimization process.On the basis of optimal SPS structure,the SPS side structure has been employed and the crashworthiness of SPS side structure and the original side structure are compared and evaluated.The main research contents are as follows:(1)The optimization method used in the crashworthiness optimization process of ship structure is introduced.Considering the characteristics of collision load,the radial basis function model which is suitable for solving nonlinear optimization problems with high accuracy is selected to obtain the approximate relationship between variables and response of structure.The main procedures of establishing radial basis function model are introduced in detail,such as Design of Experiment,model establishment and accuracy evaluation of model.In order to realize the crashworthiness optimization of SPS hull structure,the basic principle and implementation process of multi-objective particle swarm optimization algorithm are introduced.(2)Collision test of SPS structure is carried out.Taking the stiffened plate as the replacement target,SPS structure is designed based on the principle of equivalent mass.To evaluate crashworthiness of SPS structure and stiffened plate,the deformation mode and final deformation of SPS structure and stiffened plate are analyzed and compared.(3)The collision finite element model of SPS structure is established,and the reliability of the simulation results is verified based on the test data.Based on the numerical simulation results,the damage process of SPS structure under impact load is analyzed,and the crashworthiness indexes such as energy absorption and peak impact force of SPS structure and stiffened plate are compared.The results show that the crashworthiness of SPS structure is better than that of stiffened plate.(4)The parametric analysis of SPS structure is carried out to investigate the influence of size parameters on the overall crashworthiness of SPS structure,which provides reference for the optimal design of SPS structure.Combined with the optimal Latin Hypercube design,radial basis function model and multi-objective particle swarm optimization algorithm,the multi-objective optimization process of hull structure is formed to realize the crashworthiness optimization of SPS structure.(5)The alternative design scheme of the SPS side structure is obtained by introducing the optimal SPS structure into the design of the side structure.After comparing the crashworthiness indexes of the original side structure and the SPS side structure,it is verified that the structural integrity and energy absorption of SPS side structure under same collision load are better than those of the original side structure,and the crashworthiness of SPS side structure is better.