Accession Number : ADA182713

Title :   Dynamics and Aeroelasticity of Composite Structures.

Descriptive Note : Final rept. 1 Jul 85-30 Jun 86,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE TECHNOLOGY LAB FOR ADVANCED COMPOSITES

Personal Author(s) : Chen,Gun-Shing ; Dugundji,John

PDF Url : ADA182713

Report Date : 22 Apr 1987

Pagination or Media Count : 209

Abstract : An analytical and experimental investigation was made of the aeroelastic flutter and divergence behavior of a forward swept graphite/epoxy wing aircraft with rigid body freedoms in free flight. Analytically, a transient aeroelastic analysis, using a Rayleigh Ritz formulation, modified strip theory and measured aircraft aerodynamic derivatives, was developed to predict and interpret the aeroelastic behavior and instability mechanisms. The transient aerodynamics approximated the Theodoresen function by Pade approximants and used augmented state variables to investigate stability by standard linear eigenvalue analysis. Some effects of aeroelastic tailoring, wing frequencies, rigid body modes, static stability margins, and inertial coupling effects were explored. Experimentally, a generic, full-span, 30 degree forward swept wing aircraft model allowing both rigid body pitch and plunge was constructed and tested in MIT's low speed wind tunnel. The effects of aeroelastic tailoring were demonstrated by using wings with different ply layups, which covered a range of bending-twisting coupling.

Descriptors :   *AEROELASTICITY, *COMPOSITE STRUCTURES, *SWEPTFORWARD WINGS, *AIRCRAFT MODELS, EXPERIMENTAL DESIGN, DYNAMICS, COUPLING(INTERACTION), INERTIA, LOW VELOCITY, WIND TUNNELS, FLUTTER, AERODYNAMICS, AIRCRAFT, DERIVATIVES(MATHEMATICS), AUGMENTATION, VARIABLES, FREE FLIGHT, STABILITY, RIGIDITY, LAMINATED PLASTICS, MATHEMATICAL MODELS, LIFT, GRAPHITE, EPOXY COMPOSITES, WIND TUNNEL TESTS, FINITE ELEMENT ANALYSIS, MATRIX THEORY, PERFORMANCE TESTS, VIBRATION, THEORY, EIGENVALUES, LINEAR SYSTEMS, TRANSIENTS, FREQUENCY, WINGS, PITCH(MOTION)

Subject Categories : Research and Experimental Aircraft
      Laminates and Composite Materials
      Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE