Optimization of compound pressure cylinders

Purpose: The purpose of this paper is optimization of the weight of compound cylinder for a specific pressure. The variables are shrinkage radius and shrinkage tolerance. Design/methodology/approach: SEQ technique for optimization, the finite element code, ANSYS for numerical simulation are employed to predict the optimized conditions. The results are verified by testing a number of closed end cylinders with various geometries, materials and internal pressures. Findings: The weight of a compound cylinder could reduce by 60% with respect to a single steel cylinder. The reduction is more significant at higher working pressures. While the reduction of weight is negligible for k<2.5, it increases markedly for 2.5<k<5.5. The stress at the internal radii of the outer and inner cylinders become equal to the yield stresses of the materials used for compound cylinders. The experimental results showed higher bursting pressure for optimized cylinders Research limitations/implications: The research must be done for non-linear material models and for multiple compound cylinders Practical implications: The results can be used for high pressure vessels such as artillery tubes, gun barrels and son on. Originality/value: The numerical results indicated that for an optimum condition, the stress at the internal radii of the outer and inner cylinders become equal to the yield stresses of the materials used for compound cylinders.