Abstract
This work concerns a new tool for the automatic design of minimum weight spare parts, under geometrical and mechanical constraints. A fast method is proposed for this topological optimization in case of shells. Thus, the request of rapidity for design stage preliminaries is satisfied in this case. It has successfully solved industrial situations involving about 3,000 unknowns. In the considered approach, the topology of the structure is characterized by an unknown thickness distribution: holes correspond to null thicknesses. Avoiding plastic failure leads to characterize the thickness distribution as solution of an algebraic equation and frequencies constraint to be treated by a dual method.