Optimal design of a thick-walled pipeline cross-section against creep rupture (Q1084959)

Cylinder under combined loadings (presure, bending, axial force) is subject to nonlinear creep described by Norton-Odqvist creep law. In view of bending a circularly-symmetric cross-section is no longer optimal in this case. Hence we optimize the shape of the cross-section; minimal area being the design objective under the constraint of creep rupture. Kachanov-Sdobyrev hypothesis of brittle creep rupture is applied. The solution is based on the perturbation method (expansion into double series of small parameters), adjusted to optimization problems.