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Attention is given to current methodology applied to the integration of the optimal design process for structures and controls. Multilevel linear decomposition techniques proved to be most effective in organizing the computational efforts necessary for ISCD (integrated structures and control design) tasks. With the development of large orbiting space structures and actively controlled, high performance aircraft, there will be more situations in which this concept can be applied.

An approach to the integration of two design activities, structural design and active control design, for a highly idealized aeroservoelastic system is presented. The particular design goal for this study is the maximization of the stable airspeed envelope of an idealized model of an aeroservoelastic system through rational and systematic variation of structural and control design parameters. The steady-state linear quadratic regulator is used to model the control subsystem; the structural subsystem is assigned characteristic design parameters, such as shear center position. The application of the procedure described here produces optimally controlled structures with stability characteristics superior to those of open-loop and initial closed-loop designs.

Previously cited in issue 19, p. 2977, Accession no. A82-39102

This paper describes potential vehicle instability modes for forward swept wing aircraft and other divergence prone aircraft. Examples show that either body-freedom flutter or aircraft aeroelastic divergence may occur depending upon the airplane planform geometry and mass distribution. These vehicle instabilities may occur at speeds very different than the clamped wing aeroelastic divergence speed.