Accession Number:

ADA172423

Title:

Modelling of Rigid-Body and Elastic Aircraft Dynamics for Flight Control Development.

Descriptive Note:

Master's thesis,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s):

• Cerra,John J. , II

Report Date:

1986-06-01

Pagination or Media Count:

118.0

Abstract:

The purpose of this effort was to provide a method of developing a linear model of an elastic aircraft. The model provides the capability to analyze the coupling between the rigid and elastic motion of the aircraft. The method developed in this effort obtains stability derivatives directly from unsteady aerodynamic forces. This results in a state space model whose states are just the normal aircraft states and rates, the structural coordinates and rates, and the control surface positions and rates. Using a representation of the YF-17 wind tunnel flutter model, it was demonstrated that the methodology developed predicted the required dynamics to make this a viable method of modelling rigid body and flutter behavior of the model. Flutter control laws were designed for motion about an equilibrium condition represented by a velocity 20 above the flutter velocity. Both classical and modern techniques yielded acceptable control laws. The control laws were also analyzed at off design conditions to check robustness. Keywords Aeroelasticity Airplane models Aerodynamic Stability Flight Controls Systems Theses.

Descriptors:

• *AEROELASTICITY
• VELOCITY
• COUPLING(INTERACTION)
• LINEAR SYSTEMS
• STEADY STATE
• CONTROL SYSTEMS
• AIRCRAFT
• FLIGHT CONTROL SYSTEMS
• MODELS
• DYNAMICS
• AERODYNAMIC STABILITY
• STRUCTURES
• ELASTIC PROPERTIES
• THESES
• COORDINATES
• VIABILITY
• AERODYNAMIC FORCES
• CONTROL THEORY
• AIRCRAFT MODELS
• RIGIDITY
• FLUTTER
• CONTROL SURFACES

Subject Categories:

• Aircraft

Distribution Statement:

APPROVED FOR PUBLIC RELEASE