Annular rotating disks optimal with respect to mixed creep rupture

Optimal shapes in the class of polynomial functions for rotating annular disks with respect
to the mixed creep rupture time are found. Two effects leading to damage: diminishing of
transversal dimensions and growth of micro-cracks are simultaneously taken into account.
The first of them requires the finite strain analysis, the latter is described by Kachanov’s
evolution equation. Behaviour of the material is described by nonlinear Norton’s law, generalized
for true stresses and logarithmic strains, and the shape change law in form of similarity
of true stresses and logarithmic strains deviators. For optimal shapes of the disk, changes
of geometry and a continuity function are presented. The theoretical considerations based
on the perception of the structural components as some highlighted objects with defined
properties is presented.