Buckling of steel-composite cylindrical pressure hulls with initial delamination.

• Buckling behavior of delaminated steel-composite cylinders was experimentally explored. • Influence of delaminated parameters on the buckling behavior was numerically discussed. • Practical equations were proposed to evaluate the linear and nonlinear buckling loads. • Practical equations to evaluate the buckling loads were developed by statistical models. This study investigated the buckling behavior of steel–composite cylindrical pressure hulls with initial delamination. Hydrostatic tests were conducted on three groups of steel–composite cylindrical pressure hulls with different delamination parameters, and the study determined the relationships between the delamination parameters and buckling behavior of delaminated pressure hulls. Numerical analyses were conducted using linear subspace and nonlinear Riks methods, followed by a comprehensive comparison of the numerical and experimental results. Numerical and response surface analyses were conducted, and two sets of practical equations were proposed to evaluate the linear and nonlinear buckling loads of steel–composite cylindrical pressure hulls. The results indicated that initial delamination reduced the buckling loads by 50 %, with the ratio of delamination length to total length being the key factor determining the nonlinear buckling loads of delaminated steel–composite cylindrical pressure hulls. [ABSTRACT FROM AUTHOR]