Static condensation in modal-based structural optimization

The modal-based structural optimization method with static aeroelastic and stress constraints is expanded to include Guyan's static condensation option. Unlike in the regular discrete-coordinate approach, where the condensation is just a numerical option with no effect on the static results, it does affect the modal-based results through its effects on the modes taken into account. It is shown that in many cases the condensation is not effective and may increase the modal-based errors. However, when applied to structural parts which are not subject to redesign, the condensation yields accurate results and causes a significant reduction in computation time. This facilitates extremely efficient on-line design sessions in which repeated optimization studies are performed with a given baseline structure.