robust multi-objective and multi-level optimization of complex mechanical structures

this paper presents a new approach to robust multi-objective and multi-level optimization of the design of complex mechanical structures. the optimization is at two levels: system and elements. at system-level, the robust multi-objective problem has four cost functions: on the one hand the minimization of the global mass and displacement at a fixed point of the mechanical structure, and on the other hand the maximization of both the robustness and the displacement of the mass. at element-level the robust multi-objective problem has two cost functions: minimization of the element mass and maximization of its robustness. a robust condensation technique, based on an enriched karhunen–loève condensation, is used for complex structures which require a large finite element model. in contrast to existing formulations, this new approach takes into account uncertainties in the design parameters at system-level and element-level. it also allows for the task sharing which is commonly used in structural engineering.