OPTIMIZATION OF CLAMPED RIGID-PLASTIC SHALLOW SHELLS OF PIECEWISE-CONSTANT THICKNESS

The minimum weight problem is studied under the condition that the con sidered shell has a piecewise constant thickness. The shell with free internal edge and clamped outer edge is subjected to uniformly distrib uted internal pressure. Moderately large deflections are taken into ac count and a deformation-type theory of plasticity is employed. The opt imization problem includes the additional restriction, which demands t hat the maximal deflections of the shell of piecewise constant thickne ss and of the reference shell, of constant thickness, coincide. Employ ing the variational methods of the optimal control theory, necessary o ptimality conditions are established. The results obtained are used to establish the optimal parameters for the shell of piecewise constant thickness.