Accession Number : ADA254285


Title :   Nonlinear Aeroelasticity of Composite Structures


Descriptive Note : Final rept. 1 Jul 1986-31 Jan 1991


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


Personal Author(s) : Dunn, Peter E ; Dugundji, John


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a254285.pdf


Report Date : Oct 1991


Pagination or Media Count : 24


Abstract : The nonlinear, stalled, aeroelastic behavior of rectangular, graphite/epoxy, cantilevered plates with varying amounts of bending-torsion stiffness coupling and with NACA 0012 Styrofoam airfoil shapes is investigated for low Reynolds number flow (200,000). A general Rayleigh-Ritz formulation is used to calculate point load static deflections, and nonlinear static vibration frequencies and mode shapes for varying tip deflections. Nonlinear lift and moment aerodynamics are used in the context of the Rayleigh-Ritz formulation to calculate static airload deflections. The nonlinear, stalled ONERA model using non-constant coefficients - initially developed by Tran and Petot - is reformulated into a harmonic balance form and compared against a time-marching Runge-Kutta scheme. Low angle-of-attack, linear flutter calculations are done by applying Fourier analysis to extract the harmonic balance method and a Newton- Raphson solver to the resulting nonlinear. Rayleigh-Ritz aeroelastic formulation.


Descriptors :   *STALLING , *FLUTTER , *GRAPHITE EPOXY COMPOSITES , *COMPOSITE WINGS , FREQUENCY , ANGLES , VIBRATION , MODELS , LAMINATES , STIFFNESS , FORMULATIONS , ATTACK , SHAPE , HARMONICS , DEFLECTION , COMPOSITE STRUCTURES , MOMENTS , GRAPHITE , ANGLE OF ATTACK , BENDING , AIRFOILS , LOW ANGLES , COUPLINGS , AERODYNAMICS , TORSION , FOURIER ANALYSIS , REYNOLDS NUMBER , STATICS , LIFT , NUMBERS , NONLINEAR ANALYSIS , FLOW , BEHAVIOR , BALANCE , CONSTANTS , COEFFICIENTS , PLATES , TIME , AEROELASTICITY , THREE DIMENSIONAL


Subject Categories : Aerodynamics
      Aircraft
      Laminates and Composite Materials


Distribution Statement : APPROVED FOR PUBLIC RELEASE