Optimal Design of Disks Under Large Creep Deformation

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