Advantages of double-sided different curvature corrugated shells in stability: hydrostatic pressure tests and deformation failure mechanisms

Based on the thickness variation characteristics of the turritella bacillum shells, a double-sided different curvature (DSDC) corrugated shell was designed. It can overcome the premature fracture failure observed in the internal corrugated shells and the uniformly thick corrugated shells during buckling. It can improve buckling performance and modify failure modes. Hydrostatic pressure tests were conducted on the DSDC corrugated shell, and the failure modes were analyzed. The calculation equations for unit stiffness and equivalent stiffness are provided, and the variation patterns of stiffness in the principal directions are analyzed. The load-to-weight ratio of the corrugated shell was analyzed, revealing the influence of the corrugated morphology on buckling behavior. The DSDC corrugated shell exhibits a dual effect of local curvature and local thickness. The peaks have negative Gaussian curvature but maximum thickness, supporting the overall structure like stiffeners. The troughs have positive Gaussian curvature and minimum thickness, allowing for large local deformations. The rational distribution of materials and local curvature improvements enhance the buckling performance of cylindrical shells, contributing to the lightweight design of the shell structure. The research results are encouraging and significant for the innovative development of corrugated shells.