Rotorcraft blade lag damping using highly distributed tuned vibration absorbers

Chad A. Hebert, George A. Lesieutre

Research output: Contribution to journalConference article

9 Citations (Scopus)

Abstract

Damping of the rotor blade lag mode is especially critical in soft in-plane rotors. Lag damping is typically provided by hydraulic or elastomeric dampers. An alternative approach to providing damping over a broadband frequency range is presented. This is accomplished with multiple individual vibration absorbers which are highly distributed, both in space and in frequency. The mass for the absorbers could perhaps come from a portion of the mass of the leading edge weight structure already incorporated into the blade. The absorber system is modeled as frequency dependent mass which is distributed continuously along an elastic blade. The amount of damping can be controlled by varying the number of discrete tuning frequencies, the mass per unit length of the absorber system, the loss factor of the spring material and the frequency range of the absorbers. Through careful selection of these design parameters, substantial damping over a broad frequency range may be obtained. In an initial concept, these absorbers are embedded inside the blade leading edge weight structure, which reduces total rotor weight, complexity and drag. In addition, future research issues critical to the effective implementation of this concept are addressed.

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Vibrations (mechanical)
Damping
Rotors
Turbomachine blades
Drag
Tuning
Hydraulics

All Science Journal Classification (ASJC) codes

  • Architecture
  • Materials Science(all)
  • Aerospace Engineering
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

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title = "Rotorcraft blade lag damping using highly distributed tuned vibration absorbers",
abstract = "Damping of the rotor blade lag mode is especially critical in soft in-plane rotors. Lag damping is typically provided by hydraulic or elastomeric dampers. An alternative approach to providing damping over a broadband frequency range is presented. This is accomplished with multiple individual vibration absorbers which are highly distributed, both in space and in frequency. The mass for the absorbers could perhaps come from a portion of the mass of the leading edge weight structure already incorporated into the blade. The absorber system is modeled as frequency dependent mass which is distributed continuously along an elastic blade. The amount of damping can be controlled by varying the number of discrete tuning frequencies, the mass per unit length of the absorber system, the loss factor of the spring material and the frequency range of the absorbers. Through careful selection of these design parameters, substantial damping over a broad frequency range may be obtained. In an initial concept, these absorbers are embedded inside the blade leading edge weight structure, which reduces total rotor weight, complexity and drag. In addition, future research issues critical to the effective implementation of this concept are addressed.",
author = "Hebert, {Chad A.} and Lesieutre, {George A.}",
year = "1998",
month = "1",
day = "1",
language = "English (US)",
volume = "4",
pages = "2452--2457",
journal = "Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference",
issn = "0273-4508",
publisher = "American Institute of Aeronautics and Astronautics Inc. (AIAA)",

}

TY - JOUR

T1 - Rotorcraft blade lag damping using highly distributed tuned vibration absorbers

AU - Hebert, Chad A.

AU - Lesieutre, George A.

PY - 1998/1/1

Y1 - 1998/1/1

N2 - Damping of the rotor blade lag mode is especially critical in soft in-plane rotors. Lag damping is typically provided by hydraulic or elastomeric dampers. An alternative approach to providing damping over a broadband frequency range is presented. This is accomplished with multiple individual vibration absorbers which are highly distributed, both in space and in frequency. The mass for the absorbers could perhaps come from a portion of the mass of the leading edge weight structure already incorporated into the blade. The absorber system is modeled as frequency dependent mass which is distributed continuously along an elastic blade. The amount of damping can be controlled by varying the number of discrete tuning frequencies, the mass per unit length of the absorber system, the loss factor of the spring material and the frequency range of the absorbers. Through careful selection of these design parameters, substantial damping over a broad frequency range may be obtained. In an initial concept, these absorbers are embedded inside the blade leading edge weight structure, which reduces total rotor weight, complexity and drag. In addition, future research issues critical to the effective implementation of this concept are addressed.

AB - Damping of the rotor blade lag mode is especially critical in soft in-plane rotors. Lag damping is typically provided by hydraulic or elastomeric dampers. An alternative approach to providing damping over a broadband frequency range is presented. This is accomplished with multiple individual vibration absorbers which are highly distributed, both in space and in frequency. The mass for the absorbers could perhaps come from a portion of the mass of the leading edge weight structure already incorporated into the blade. The absorber system is modeled as frequency dependent mass which is distributed continuously along an elastic blade. The amount of damping can be controlled by varying the number of discrete tuning frequencies, the mass per unit length of the absorber system, the loss factor of the spring material and the frequency range of the absorbers. Through careful selection of these design parameters, substantial damping over a broad frequency range may be obtained. In an initial concept, these absorbers are embedded inside the blade leading edge weight structure, which reduces total rotor weight, complexity and drag. In addition, future research issues critical to the effective implementation of this concept are addressed.

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M3 - Conference article

AN - SCOPUS:0031678002

VL - 4

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EP - 2457

JO - Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference

JF - Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference

SN - 0273-4508

ER -