Theoretical and numerical study of the buckling of steel-composite cylindrical shells under axial compression

Steel cylindrical shells have significant applications in the field of ocean engineering. However, such shells possess lower actual load-bearing capacity due to their high sensitivity to geometric imperfection. To improve the load-bearing capacity of normal steel cylindrical shells, steel-composite cylindrical shells were proposed in this work, and their buckling behaviours under axial compression were investigated in depth. The theoretical formula of the linear elastic buckling for the steel-composite cylindrical shells was derived. The linear bucking numerical analyses were conducted to verify the correctness of theoretical solution. The imperfection sensitivity of the steel-composite cylindrical shells were also examined by nonlinear buckling numerical analyses. Results show that the maximum average deviation between the theoretical and linear numerical values did not exceed 20 % for all considered models, and most of the average deviations were lower than 10 %. This exhibited a good agreement between the theoretical prediction and numerical simulation. Compared to the normal steel cylindrical shell, the steel-composite cylindrical shell possessed lower imperfection sensitivity and higher load carrying capacity. These findings can provide theoretical guidance for designing and evaluating steel-composite cylindrical shells under axial compression.