Aeroelasticity (eBook)

CHAPTER 1. INTRODUCTION TO AEROELASTICITY1-1 Definitions1-2 Historical background1-3 Influence of aeroelastic phenomena on design1-4 Comparison of wing critical speedsCHAPTER 2. DEFORMATIONS OF AIRPLANE STRUCTURES UNDER STATIC LOADS2-1 Introduction2-2 Elastic properties of structure2-3 Deformation due to several forces. Influence coefficients2-4 Properties of influence coefficients2-5 Strain energy in terms of influence coefficients2-6 Deformations under distributed forces. Influence functions2-7 Properties of influence functions2-8 The simplified elastic airplane2-9 Deformations of airplane wings2-10 Integration by weighting matrices2-11 Energy methods in deflection calculations2-12 Deformations of slender unswept wings2-13 Influence functions and coefficients of slender swept wings2-14 Deformations and influence coefficients of low aspect-ratio wings2-15 Influence coefficients of complex built-up wings by the principle of minimum strain energy2-16 Influence coefficients of complex built-up wings by the principle of minimum potential energy2-17 Calculation of deformations of solid wings of variable thickness and complex built-up wings by the Rayleigh-Ritz methodCHAPTER 3. DEFORMATION OF AIRPLANE STRUCTURES UNDER DYNAMIC LOADS3-1 Introduction3-2 Differential equations of motion of a beam3-3 Integral equation of motion of a slender beam3-4 Dynamic equilibrium of slender rotating beams in torsion3-5 Dynamic equilibrium of slender beams in torsion3-6 Dynamic equilibrium of restrained airplane wing3-7 Dynamic equilibrium of the unrestrained elastic airplane3-8 Energy methods 3-9 Approximate methods of solution to practical problems3-10 Approximate solutions by the Rayleigh-Ritz method3-11 Approximate solutions by the lumped parameter methodCHAPTER 4. APPROXIMATE METHODS OF COMPUTING NATURAL MODE SHAPES AND FREQUENCIES4-1 Introduction4-2 Natural modes and frequencies by energy methods4-3 Natural mode shapes and frequencies derived from the integral equation4-4 Natural mode shapes and frequencies derived from the differential equation4-5 Solution of characteristic equations4-6 Natural modes and frequencies of complex airplane structures4-7 Natural modes and frequencies of rotating beamsCHAPTER 5. AERODYNAMIC TOOLS: TWO- AND THREE-DIMENSIONAL INCOMPRESSIBLE FLOW5-1 Fundamentals: the concept of small disturbances5-2 Properties of incompressible flow with and without circulation5-3 Vortex flow5-4 Thin airfoils in steady motion5-5 Finite wings in steady motion5-6 Thin airfoils oscillating in incompressible flow5-7 Arbitrary motion of the thin airfoils in incompressible flow; the gust problemCHAPTER 6. AERODYNAMIC TOOLS: COMPRESSIBLE FLOW6-1 Introduction6-2 Wings and airfoils in steady subsonic flow; the Prandtl-Glauert transformation6-3 Airfoils and wings in steady supersonic flow6-4 Oscillating airfoils in subsonic flow6-5 Arbitrary small motions of airfoils in subsonic flow6-6 Oscillating airfoils in supersonic speeds6-7 Indicial airfoil motions in supersonic flow6-8 Unsteady motion of airfoils at Mach number oneCHAPTER 7. WINGS AND BODIES IN THREE-DIMENSIONAL UNSTEADY FLOW7-1 Introduction7-2 Oscillating finite wings in incompressible flow7-3 The influence of sweep7-4 Wings of very low aspect ratio in unsteady motion7-5 The influence of sweep7-6 Unsteady motion of nonlifting bodiesCHAPTER 8. STATIC AEROELASTIC PHENOMENA8-1 Introduction8-2 Twisting of simple two-dimensional wing with aileron8-3 Slender straight wings8-4 Swept wings8-5 Low aspect-ratio lifting surfaces of arbitrary planform and stiffnessCHAPTER 9. FLUTTER9-1 Introduction. The nature of flutter9-2 Flutter of a simple system with two degrees of freedom9-3 Exact treatment of the bending-torsion flutter of a uniform cantilever wing9-4 Aeroelastic modes9-5 Flutter analysis by assumed-mode methods9-6 Inclusion of finite span effects in flutter calculations9-7 The effect of compressibility on flutter9-8 Flutter of swept wings9-9 Wings of low aspect ratio9-10 Single-degree-of-freedom flutter9-11 Certain other interesting types of flutterCHAPTER 10. DYNAMIC RESPONSE PHENOMENA10-1 Introduction10-2 Equations of disturbed motion of an elastic airplane10-3 Systems with prescribed time-dependent external forces10-4 Transient stresses during landing10-5 Systems with external forces depending upon the motion10-6 Dynamic response to a discrete gust10-7 Dynamic response to continuous atmospheric turbulenceCHAPTER 11. AEROELASTIC MODEL THEORY11-1 Introduction11-2 Dimensional concepts11-3 Equations of motion11-4 Vibration model similarity laws11-5 Similarity laws for systems under steady airloads11-6 Flutter model similarity laws11-7 The unrestrained flutter model11-8 The dynamic stability modelCHAPTER 12. MODEL DESIGN AND CONSTRUCTION12-1 Introduction12-2 Structural simulation12-3 Elastic properties as functions of one variable12-4 Elastic properties as functions of two variables12-5 Shape simulation12-6 Inertial simulationCHAPTER 13. TESTING TECHNIQUES13-1 Introduction13-2 Measurement of structural flexibility13-3 Measurement of natural frequencies and mode shapes13-4 Steady-state aeroelastic testing13-5 Dynamic aeroelastic testing - full scale13-6 Dynamic aeroelastic testing - model scaleAPPENDICES. MATHEMATICAL TOOLSA MatricesB Integration by weighting numbersC Linear systemsREFERENCESAUTHOR INDEXSUBJECT INDEX