Optimal design of trapezoid stiffeners of composite cylindrical shells subjected to hydrostatic pressure

Optimization of a composite cylindrical pressure hull subjected to hydrostatic pressure with trapezoidal stiffeners is considered in this paper. The composite cylindrical shell is fabricated with carbon fiber reinforced epoxy composite while the stiffener is made of aluminum alloy. First of all, the analytical buckling model for composite cylinders with stiffeners subjected to hydrostatic pressure is derived. Subsequently, the finite element method is used to verify the accuracy of the analytical solution through some examples. After verification, the analytical solution is coupled with the genetic algorithm and then used to optimize the cross-sectional shape of the stiffeners of the composite pressure hull to obtain the maximum buckling pressure. During the optimization process, the relationship between the buckling pressure and each geometrical parameter of the stiffener has been analyzed. The inertia moment of the stiffener section is found to have a good linear relationship with the buckling pressure. Therefore, the inertia moment is used as an objective function to optimize the cross-sectional shape of the stiffeners of the composite pressure hull, and the feasibility of this method has been proved by comparing the optimization results. With high efficiency, this method can be applied to the optimal design of the stiffener shape of a composite pressure shell.

Automated summary

This paper explores the optimization of a composite cylindrical pressure hull with trapezoidal stiffeners subjected to hydrostatic pressure. The study uses both analytical and finite element methods, coupled with genetic algorithms, to optimize the cross-sectional shape of the stiffeners to achieve maximum buckling pressure. It is found that the inertia moment of the stiffener section has a good linear relationship with the buckling pressure, serving as an effective objective function for optimization. The method is proven to be efficient and applicable for optimal design of stiffener shapes in composite pressure shells.