General Instability of Conical Shells with Non-Uniformly Spaced Stiffeners under Hydrostatic Pressure

摘要

The method of analysis of the general instability of stiffened conical shells, developed earlier by the authors for uniform and equally spaced stiffeners, is now extended to shells with non-uniformly spaced stiffeners. For hydrostatic pressure loading, rings are the most efficient stiffeners. On account of the cone geometry, equally spaced rings divide a conical shell into 'sub-shells' of unequal local buckling strength. Hence unequal spacings, which result in 'sub-shells' of equal local buckling strength, are the logical approach to an optimum structure. A rule for such spacings is derived and discussed. The analysis is then given for conical shells with rings spaced according to rules of this type. Numerical calculations are presented and discussed. A simplified approximate formula for the critical pressure is also proposed. (Author)