Abstract
The work deals with multi-step topology and sizing optimisation of stiffened elastic plates and shells. Topology optimisation provides the optimal plate and shell topology giving proper localization of stiffening zones. The problem of optimal choice of the number of stiffeners and its rigidity depends on specific design. The second stage gives directions of stiffeners. Mean moments are used to determine the optimal orientation of the stiffeners. The third step based on strict sensitivity analysis and/or topology optimization is included into the multi-step design procedure. At this point more detailed sizing of stiffeners cross-section is considered. The three-layer Kirchhoff-Lowe plate model is used with topology optimisation procedure to determine optimal stiffening zones.