Design of filament-wound spherical pressure vessels based on non-geodesic trajectories

One of the most key issues for design and production of composite spherical pressure vessels reflects on determination of the stress distributions and burst failure load of the vessels. The main objective of this study is to carry out the investigation of the stress/strain distributions and the ultimate strength analysis for filament-wound composite spherical pressure vessels based on non-geodesic winding trajectories. The non-geodesic patterns were simulated to determine the appropriate tangent points. The dome thickness distributions were precisely predicted using the cubic-spline function. The finite element model of the spherical vessel was created using the discrete method. The optimal autofrettage pressure was calculated to improve the bearing capacity of the autofrettaged vessel. The strain distributions of the composite layers at various selected locations were obtained numerically and experimentally, respectively. The burst pressure was deterministically predicted with the aid of the maximum strain criterion and was validated using the obtained experimental data. It is shown that the experimental results are in good agreements with those determined using the finite element model, which demonstrates that the present method is able to provide valuable reference for design of filament-wound spherical pressure vessels.