Parametric analysis of buckling of corrugated cylinder shell under external pressure

Cylindrical shells under external pressure are increasingly used in underwater vessels and their collapse is mainly due to the buckling phenomenon. Improving the resistance of these structures to buckle can be achieved by modifying the geometry of the structures. For reinforcement of cylindrical shells increasing the shell thickness and using ring stingers have been amongst the most popular methods. However, increased pressure and weight constraints of structures demand for more advanced methods. In this study, by corrugating of surfaces between the rings and combining the geometric factors those affecting the buckling, the effecting parameters on the critical buckling pressure of the structure were investigated. For this purpose, first a cylinder with a specific diameter and length with reinforcements of different dimensions and distances was evaluated. Then by corrugating with different radius of curvatures in inter-stiffener conditions the effect of these modifications on the buckling pressure and strength to weight ratio were investigated. The results of the analysis indicated that in the case of inter-stiffener buckling the increase of critical buckling pressure of corrugated shells is very significant. In other words, in this method the effectiveness of geometric modification is highly dependent on the inter-stiffener buckling.