Strength Analysis And Optimal Design Of The Filament Wound Pressure Vessels

The fiber-wound composite materials pressure vessels(FWPV) with metal inner liner have been widely used in the frontier military domains such as aerospace and energy chemical and other civilian areas because of its excellent performance, such as light weight, high pressure and good design performance. Therefore, the research and optimization design will be very important in both theory meaning and practical value.Different with isotropic structures such as steel cylinders, the structures of FWPV are very complex because of its anisotropic materials and the special production process. In the dome parts, both the winding angle and the thickness vary along the meridian line. In this paper, the differential equation of filament winding angle is derived based on the fiber winding theory, the differential geometry and the stress distribution of fiber. Then the formula of the fiber layer thickness and the winding angle are obtained by approximation and interpolation method. The FEM models of the FWPV are established by ANSYS software. The calculating and strength checking indicated that the danger zone of FWPV is located in the dome. A hyperelliptic function is adopted as the basis function for describing the meridian of the dome shape. The dome contour is optimized by taking the shape factor(SF) as the objective and two parameters in the basis function as the design variables. The constraints include the geometrical limitations, winding conditions and the Tsai-Wu failure criterion. The optimum design solution is obtained through the particle swarm optimization algorithm. And Influences of the slippage coefficient and the polar opening on the SF are also discussed. Finally the buckling instability of FWPV is researched when under the external load, the result shows that the ability to resist bucking has been improved by optimization of the reinforced structure.The proposed modeling and analysis method in this paper provide an effective approach for the filament wound pressure vessels. The calculation results may provide certain theoretical guidance for the production of FWPVs.