Influence of control on flexible aircraft crack growth

Author

Yu, Sibok ; Newman, Brett

Author_Institution

Dept. of Aerosp. Eng., Old Dominion Univ., Norfolk, VA, USA

Volume

5

fYear

2000

fDate

2000

Firstpage

3053

Abstract

The overall objective of this research is to investigate and assess the leverage generated by flight control loops for reducing fatigue damage and enhancing structural integrity. An analytical state space crack growth model is briefly considered first. Next, a dynamic flexible aircraft model is presented. Stress response from the aircraft is applied as input to the crack model. Design of a flight control system is also considered. Objectives of the controller are to correct deficiencies in the vehicle motion. Comparison of open-loop and closed-loop stress responses indicate the control system has substantial effect on transient stress behavior. Long-term fatigue damage and structural integrity predictions, and the influence feedback control and load have on such predictions, are made with simulation runs. A mix of open-loop and closed-loop cases with nominal and variable feedback gains, and vehicle motions including nominal maneuvers and overloads are used. Individual feedback gain values have substantial influence on crack growth

Keywords

aircraft control; control system synthesis; crack-edge stress field analysis; fatigue cracks; feedback; flexible structures; state-space methods; analytical state space crack growth model; closed-loop stress responses; dynamic flexible aircraft model; fatigue damage reduction; flexible aircraft crack growth; flight control loops; flight control system design; long-term fatigue damage; nominal maneuvers; open-loop stress responses; overloads; stress response; structural integrity; structural integrity predictions; transient stress behavior; variable feedback gains; Aerospace control; Aircraft; Control systems; Fatigue; Feedback; Motion control; Open loop systems; State-space methods; Stress control; Vehicle dynamics;

fLanguage

English

Publisher

ieee

Conference_Titel

American Control Conference, 2000. Proceedings of the 2000

Conference_Location

Chicago, IL

ISSN

0743-1619

Print_ISBN

0-7803-5519-9

Type

conf

DOI

10.1109/ACC.2000.879126

Filename

879126