Optimum Design of Submerged Cylindrical Shells Subjected to Dynamic Loadings,

摘要

This report presents a procedure for the optimum design of a submerged T-ring stiffened cylindrical shell subjected to a specified harmonic excitation and external pressure. Three different design objectives can be investigated: (1) minimum structural mass, (2) minimum structural response and (3) minimum of a linear combination of structural mass and structural response. The design variables are shell thickness, T-web depth and thickness, T-flange width and thickness, and (uniform) stiffener spacing. The design constraints are on geometric admissibility, in vacuo natural frequencies of the shell, shell buckling, and on internal stresses. Numerical studies indicate the necessity of constraining the structural mass of the cylinder if minimum structural response is the design objective, and constraints must be imposed on both structural response and maximum structural mass when the combined design objective is employed.