A New Higher-Order Composite Theory for Analysis and Design of High Speed Tilt-Rotor Blades PDF Download

Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722904371
Category :
Languages : en
Pages : 182

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Book Description
A higher-order theory is developed to model composite box beams with arbitrary wall thicknesses. The theory, based on a refined displacement field, represents a three-dimensional model which approximates the elasticity solution. Therefore, the cross-sectional properties are not reduced to one-dimensional beam parameters. Both inplane and out-of-plane warping are automatically included in the formulation. The model accurately captures the transverse shear stresses through the thickness of each wall while satisfying all stress-free boundary conditions. Several numerical results are presented to validate the present theory. The developed theory is then used to model the load carrying member of a tilt-rotor blade which has thick-walled sections. The composite structural analysis is coupled with an aerodynamic analysis to compute the aeroelastic stability of the blade. Finally, a multidisciplinary optimization procedure is developed to improve the aerodynamic, structural and aeroelastic performance of the tilt-rotor aircraft. The Kreisselmeier-Steinhauser function is used to formulate the multiobjective function problem and a hybrid approximate analysis is used to reduce the computational effort. The optimum results are compared with the baseline values and show significant improvements in the overall performance of the tilt-rotor blade. McCarthy, Thomas Robert Ames Research Center TILT ROTOR AIRCRAFT; THREE DIMENSIONAL MODELS; MULTIDISCIPLINARY DESIGN OPTIMIZATION; ROTARY WINGS; COMPOSITE STRUCTURES; MATHEMATICAL MODELS; AERODYNAMIC LOADS; AEROELASTICITY; BOX BEAMS; TRANSVERSE LOADS; THICK WALLS; STRUCTURAL ANALYSIS; PROPELLER BLADES; SHEAR STRESS; ELASTIC PROPERTIES; STRESS-STRAIN RELATIONSHIPS; RESONANT FREQUENCIES; HIGH SPEED...