Theoretical and Experimental Investigations of Internal Resonances, and Related Behavior, in Nonlinear Aeroelastic Systems

Abstract

Adverse aeroelastic responses and related instabilities may affect the performance of many advanced air vehicle configurations. These responses are linked to nonlinearities within the aeroelastic system and have resulted in responses such as store-induced limit cycle oscillations (LCOs) and residual pitch oscillations (RPOs). As concepts for future aircraft designs are pursued, the source of these instabilities must be characterized. The primary objectives of this research are to investigate the presence of nonlinear pathologies such as LCOs and system resonances in aeroelastic systems; characterize the signature of such responses in the coupled nonlinear aerodynamic, structure, structural dynamic system; and, and examine passive suppression concepts. These research activities have been directed toward an explanation of nonlinear behavior found in aircraft systems. In particular, interest has been focused on store-induced limit cycle oscillations ("wing-with-store flutter") that exist, but not predicted with current approaches. We considered an aeroelastic system that was coupled by nonlinearities, possessed an external forcing, and satisfied conditions in which the frequencies were commensurate. Also, we examined LCO's induced by continuous hardening-type nonlinearities in structural stiffness.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2004
Accession Number
ADA424124

Entities

People

  • Thomas W. Strganac

Organizations

  • Texas A&M University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aerodynamic Configurations
  • Aircraft Design
  • Aircrafts
  • Airframes
  • Engineering
  • Equations
  • Equations Of Motion
  • Fighter Aircraft
  • Frequency
  • Instability
  • Materials
  • Mechanical Properties
  • Oscillation
  • Resonance
  • Resonant Frequency
  • Stiffness
  • Vehicles

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Control Systems Engineering.
  • Systems Analysis and Design