Shape optimization of axisymmetric shells with respect to fatigue

The optimal design procedure based on the combination of the Computer Aided Geometrical Design mathematical methods for the shape definition, the Boundary Element Method used for analysis of the response quantities, assisted by the Sequential Linear Programming method with ‘move limits’ is presented in this paper. The objective of the design is the maximization of the number of cycles corresponding to crack initiation in an axisymmetric shells. The presented approach is composed of the following steps: (i) stress-strain calculation using notch correction and Mróz plasticity model, (ii) estimation of critical plane to asses of fatigue lives, and (iii) formulation of the optimization problem with constraint set on the number of cycles corresponding to the crack initiation.