Effect of rib profile on critical buckling pressure of ring-stiffened composite shells under hydrostatic pressure

The buckling behaviour of thin-walled composite cylindrical shells with different rib profiles under hydrostatic pressure is studied in this paper. Various models of composite shells with outer diameter of 324 mm, thickness of 8 mm, length of 800 mm, and 18 different rib profiles are designed. Ribs have same sectional area and the total height is no more than 18 mm. Finite element (FE) models are built and validated by published experimental and FE results. The results for above models are obtained and show that the critical buckling pressure of ring-stiffened composite shells can improve by 44% to 136% compared to that of unstiffened composite shells. The rib total height, web thickness, and rib profile type are three factors affecting the critical buckling pressure of ring-stiffened composite shells. The composite shell stiffened by groove shape can acquire maximum buckling-carrying capacity.