Evaluation of innovative concepts for semi-active and active rotorcraft control

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Please use this identifier to cite or link to this item: http://hdl.handle.net/1853/42893

Title: Evaluation of innovative concepts for semi-active and active rotorcraft control
Author: Van Weddingen, Yannick
Abstract: Lead-lag dampers are present in most rotor systems to provide the desired level of damping for all flight conditions. These dampers are critical components of the rotor system, and the performance of semi-active Coulomb-friction-based lead-lag dampers is examined for the UH-60 aircraft. The concept of adaptive damping, or “damping on demand,” is discussed for both ground resonance and forward flight. The concept of selective damping is also assessed, and shown to face many challenges. In rotorcraft flight dynamics, optimized warping twist change is a potentially enabling technology to improve overall rotorcraft performance. Research efforts in recent years have led to the application of active materials for rotorcraft blade actuation. An innovative concept is proposed wherein the typically closed section blade is cut open to create a torsionally compliant structure that acts as its own amplification device; deformation of the blade is dynamically controlled by out-of-plane warping. Full-blade warping is shown to have the potential for great design flexibility. Recent advances in rotorcraft blade design have also focused on variable-camber airfoils, particularly concepts involving “truss-core” configurations. One promising concept is the use of hexagonal chiral lattice structures in continuously deformable helicopter blades. The static behavior of passive and active chiral networks using piezoelectric actuation strategies is investigated, including under typical aerodynamic load levels. The analysis is then extended to the dynamic response of active chiral networks in unsteady aerodynamic environments.
Type: Dissertation
URI: http://hdl.handle.net/1853/42893
Date: 2011-11-14
Publisher: Georgia Institute of Technology
Subject: Lead-lag dampers
Morphing rotor blades
Rotorcraft
Active twist blades
Chiral lattice networks
Damping (Mechanics)
Vibration (Aeronautics) Damping
Rotors Dynamics
Blades
Department: Aerospace Engineering
Advisor: Committee Chair: Bauchau Olivier; Committee Co-Chair: Ruzzene Massimo; Committee Member: Costello Mark; Committee Member: Hodges Dewey; Committee Member: Ozbay Serkan
Degree: PhD

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