Design Of Composite Pressure-resistant Shell

Pressure hull has been widely used in life and military because of its structural stability and strength,and it has become an indispensable part in aviation and navigation.In order to meet the requirements of our army's underwater individual combat,the pressure hull needs to be light weight and high strength.However,the traditional pressure hull is made of high strength steel,high strength aluminum alloy and so on,however,as a new kind of material,Its strength and modulus are higher than other metal materials and it has complex design,the utility model is suitable for the design requirements of the pressure-resistant shell in this subject.Therefore,a composite pressure-resistant shell is proposed in this paper,which is of great significance to the application of composite materials in military field.In this paper,the optimization design of the shell structure is accomplished through the finite element simulation of the shell.The main contents are as follows:Firstly,the overall design and theory of pressure hull are analyzed.According to the original pressure shell structure,the overall design goal and design principle of the pressure shell structure are introduced.The optimized pressure shell not only needs to ensure the strength of the original pressure shell,but also needs to reduce the weight.The T700 carbon fibre epoxy composite was selected and the molding process was selected as the corresponding molding process.In order to ensure the sealing property of the shell,The subject select the mixed connections.By comparing the characteristics of different failure criteria of composites,Hashin failure criterion is finally selected.Then,finite element analysis of the pressure vessel is carried out by using ABAQUS simulation software.The finite element analysis of metal pressure shell shows that the maximum deformation is 0.5143 mm,which lays a foundation for the design and optimization of composite pressure shell.Based on the general laying principle,the finite element analysis of composite pressure shell with different layering order was carried out.Finally,the layering order of [-45°/90°/45°/0°/-45°/0°/45°/0°]s was selected according to the simulation results,the results show that the strength of the composite pressure shell reaches the requirement when the thickness of the shell is 5mm,and the maximum deformation is 0.3407 mm.Finally,the pressure-resistant composite shell was optimized.In order to increase the strength and reduce the weight of the composite pressure shell,the structure of the2 mm thick composite pressure shell was designed,and the strength of the composite pressure shell was enhanced by the design of the built-in supporting structure.The results show that when five longitudinal beams are designed at the bottom of the frame and two longitudinal beams are designed at both sides,the strength of the shell is up to the requirement and the maximum deformation is 0.5025 mm.Therefore,the maximum deformation and weight of the composite pressure shell are reduced by 88.5% and42.5% respectively when the composite pressure shell is fitted with a frame structure.