Theoretical, numerical, and experimental analyses of the buckling of thin-walled sandwich cylindrical shells subjected to external pressure

Cylindrical shells find wide application in ocean engineering because of their straightforward geometry and mature processing. This study examined the buckling response of thin-walled sandwich cylinder configurations. To predict the linear elastic buckling load, a theoretical formula was derived and validated through comparison with linear buckling numerical analyses. The mean difference between the theoretical and linear numerical prognoses for all the considered geometric parameters was 13 %, demonstrating favorable consistency. Three sandwich cylindrical shells with nominally identical geometric parameters were fabricated, measured, and tested. Nonlinear numerical analyses for scanned models of the three samples were also conducted. The collapse pressures of the three fabricated samples were approximately 3 MPa, and the samples collapsed by forming a dent near the welding seam area. The buckling characteristics of the samples were consistent with the nonlinear numerical data and could be predicted by the theoretical formula after modification. These findings can provide theoretical guidance regarding the utilization of thin-walled sandwich cylindrical shells.