Low Frequency Instabilities of Free Systems

Item

Title
Low Frequency Instabilities of Free Systems
Date
1963
Index Abstract
Coming Soon
Photo Quality
Not Needed
Report Number
ASD TDR 63-655
Creator
Schwendler, Robert G.
Hill, Jack H.
Corporate Author
Computer Engineering Associates
Laboratory
AF Flight Dynamics Laboratory
Extent
127
Identifier
AD0426543
Access Rights
OTS
Distribution Classification
1
Contract
AF 33(657)-8293
DoD Project
8219
DoD Task
821901
DTIC Record Exists
Yes
Distribution Change Authority Correspondence
None
Distribution Conflict
No
Abstract
This report contains an investigation of "mode interaction" instabilities of aircraft. "Mode interaction" refers to coupling between an elastic mode and a rigid body mode of the free system. Three rather general airframe configurations are analyzed in detail. It is shown that systems which tend toward steady state divergence are particularly susceptible to mode interaction. Also, that aerodynamic damping terms can have a destabilizing effect upon a free system. The analyses show that aeroelastic systems which possess no finite frequency elastic mode can be susceptible to a finite frequency instability. Computer studies of several different airframe configurations are discussed. An appendix to the report contains stability charts for an aircraft having two rigid body modes and one elastic mode.
Report Availability
Full text available
Date Issued
1963-11
Provenance
Lockheed Martin Missiles & Fire Control
Type
report
Format
1 online resource
Media
ASDTDR63-655.pdf

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