Weight and Cost Optimization of Hydrostatically Loaded Stiffened Flat Plates

Plates with longitudinal or orthogonal tee-stiffeners subjected to differential pressure are used in many structures. Equations to achieve minimum weight and cost are presented. Energy methods and plate gridwork theory are used. The accuracy of the technique is verified for typical designs by excellent comparison with stresses calculated by finite-element analysis. Minimum weight and cost studies using an optimization program are presented. Numerous small stiffeners minimize weight, whereas fewer, large stiffeners minimize cost. Fifteen independent structural variables are used for orthogonally stiffened plates. Stress, deflection, stability, and minimum thickness constraints are applied. Rapid optimum designs are achieved economically.