Comment on ‘optimum structural design of CFRP isogrid cylindrical shell using genetic algorithm’

We comment on the paper published by Sakata et al., in J. Adv. Compos. Mater., 2018, 27, 35–51, which was in continuation of the previous work by Sakata and Ben in J. Adv. Compos. Mater., 2012, 21, 445–457. Although the experimental section in both works were identical, the reported numerical values of the linear buckling loads differed. In addition, all the specimens were manufactured using an identical process by employing silicone rubber mold and filament winding technique, and outer skin layers and stiffeners consisted of a fixed number of plies. Nonetheless, different shell thicknesses and stiffeners cross-sectional areas were reported for the specimens. Since the buckling behavior of cylindrical shells is highly sensitive to their thickness, the difference in the reported numerical linear buckling loads of the mentioned studies could be due to different thickness values used as inputs for their numerical analyses. In order to address this subject, the present study aimed to provide complete and comprehensive data on the buckling behavior of unstiffened and grid-stiffened cylindrical shells with the same material properties and geometrical dimensions but various thicknesses. The presented results can be used as a benchmark for future studies.