Optimal Design And Experimental Analysis Of The Ring-stiffened Pressure Shell Of Long-range Underwater Glider

As a new type of ocean observation platform,the underwater glider can adjust its own buoyancy to achieve the submerged and floating movement,which has the advantages of controllable track,long battery life and low cost.During the dive process of the underwater glider,the pressure-resistant shell will be compressed and deformed by the seawater temperature and seawater pressure,thereby reducing its buoyancy.The compression deformation of the pressure-resistant shell directly affects the accuracy of the buoyancy control of the underwater glider,Analysis of the compression deformation of the pressure-resistant shell under the effect of thermal and mechanical coupling can improve the accuracy of the buoyancy control of the underwater glider,reduce unnecessary energy consumption,and thereby improve the economy of navigation;on the other hand,the rearrangement of the pressure-resistant shell The ratio will affect its energy carrying capacity.By optimizing the structure of the pressure-resistant housing,the rearrangement ratio of the pressure-resistant housing can be reduced,the energy carrying capacity can be improved,and the voyage of the underwater glider can be improved.Therefore,under the premise of meeting the requirements of use,the optimal design of the pressure-resistant shell is of great significance for improving the endurance of the underwater glider.The main research contents and results of this article are as follows:(1)Taking the pressure-resistant shell of the "Haiyan-L" long-range underwater glider as the object,according to the stability theory of the shell,a lightweight scheme for circumferentially ribbed inside the cylindrical shell is proposed.Six design parameters related to strength,stability and shell quality are selected,and the central composite design method is used for experimental design.A regression equation is established based on the experimental results,and each design variable is obtained using the Sobol’ sensitivity index based on the quasi-Monte Carlo method Local sensitivity and global sensitivity.(2)According to the results of sensitivity analysis,four parameters with higher global sensitivity coefficients are selected as optimization variables,with strength,stability and space utilization as constraints,and the minimum mass as the optimization goal.The body is optimized,and compared with the conventional cylindrical pressure shell with the same drainage volume,the weight is reduced by about 9.4%.(3)Using ANSYS Workbench simulation analysis to verify the strength and stability of the optimized pressure-resistant shell;combining simulation analysis and experimental testing,the combined effects of seawater depth,temperature and density on the volumetric compression deformation and buoyancy of the pressure shell are obtained law.