I. Herszberg, M. Karpel

Analytical expressions for the sensitivity derivatives of flutter dynamic pressure and control design criteria, with respect to structural and control design variables are extended to deal with residualized aeroservoelastic models. The model considered is a first-order time-domain feedback system subject to model size reduction by means of residualization. The structure is represented by a number of structural vibration modes, the aerodynamics by rational approximation functions. The control system couples control surface motion to the response of motion sensors located on the structure. The dynamic residualization technique and the minimum-state approximation method for aerodynamic modelling have been demonstrated to yield a relative low order, high accuracy model which may be used for on-line design studies where fast response time is important. In the optimum design process for aeroservoelastic systems, considerable computation time is spent on calculating stability derivatives. The extended formulation and new techniques of this work make the calculations more efficient and further enhance on-line studies. A realistic numerical example of the optimal design of an aeroservoelastic system comprising a carbon-composite wing with four control surfaces is used to assess the performance of this method. The optimization minimizes the structural weight with respect to structural and control variables, subject to aeroelastic, control and structural design constraints. The use of sensitivity derivatives calculated for the reduced system decreases significantly the time taken for the optimization, and consequently enhances the optimization method as an on-line design tool.

International Forum on Aeroelasticity and Structural Dynamics 1991, Aachen

Conference Paper

englisch

21,0 x 29,7 cm, 8 Seiten

DGLR-Bericht, 1991, 1991-06, International Forum on Aeroelasticity and Structural Dynamics 1991 Proceedings; S.371-378; 1991; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroelasticity

Bestellbar

1991