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Optimal redesign study of the harm wingThe purpose of this project was to investigate the use of optimization techniques to improve the flutter margins of the HARM AGM-88A wing. The missile has four cruciform wings, located near mid-fuselage, that are actuated in pairs symmetrically and antisymmetrically to provide pitch, yaw, and roll control. The wings have a solid stainless steel forward section and a stainless steel crushed-honeycomb aft section. The wing restraint stiffness is dependent upon wing pitch amplitude and varies from a low value near neutral pitch attitude to a much higher value at off-neutral pitch attitudes, where aerodynamic loads lock out any free play in the control system. The most critical condition for flutter is the low-stiffness condition in which the wings are moved symmetrically. Although a tendency toward limit-cycle flutter is controlled in the current design by controller logic, wing redesign to improve this situation is attractive because it can be accomplished as a retrofit. In view of the exploratory nature of the study, it was decided to apply the optimization to a wing-only model, validated by comparison with results obtained by Texas Instruments (TI). Any wing designs that looked promising were to be evaluated at TI with more complicated models, including body modes. The optimization work was performed by McIntosh Structural Dynamics, Inc. (MSD) under a contract from TI.
Document ID
19870002301
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Mcintosh, S. C., Jr.
(McIntosh Structural Dynamics, Inc. Palo Alto, CA, United States)
Weynand, M. E.
(Texas Instruments, Inc. Lewisville, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1984
Publication Information
Publication: NASA. Langley Research Center Recent Experiences in Multidisciplinary Analysis and Optimization, Part 1
Subject Category
Aircraft Design, Testing And Performance
Accession Number
87N11734
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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