Impedance Matched Mass-Dampers: A New Approach For Improving Structural Damping
Report Number: WL-TR-91-3078 Volume I, p. DAA-1 thru DAA-20
Author(s): Gardner, Craig, Lyon, Richard H.
Corporate Author(s): General Eletric-Power Generation, Massachusetts Institute of Technology
Laboratory: Wright Laboratory
Date of Publication: 1991-08
Pages: 20
Contract: Laboratory Research - No Contract
DoD Project: 2401
DoD Task: 240104
Identifier: This paper is part of a conference proceedings. See ADA241311
Abstract:
Statistical Energy Analysis (SEA) techniques are used to analytically determine the damping effect achieved by attaching a quantity of mass-dampers to a damped flat plate. Mass-dampers are defined as SDOF oscillators which are over damped and have a resonant frequency below the frequency range of interest. The analysis has shown that the damping effect achieved by this approach is maximized when damper impedance is matched to a particular ratio of the average drive point impedance of the plate. The analysis indicates that the damping effect achieved is significant for mass-damper mass to plate mass ratios as low as 0.05 to 0.2. A prototype mass-damper system was designed and tested to verify the analytical results. The experimental results showed that significant improvements in damping were achieved and that the amplitude of modal frequencies were reduced by as much as 10-15 dB over a wide frequency range. This approach differs from visco-elastic techniques in that it does not share strain energy with base structure. This characteristic may make this approach ·effective for damping stiff structures at low frequencies.
Author(s): Gardner, Craig, Lyon, Richard H.
Corporate Author(s): General Eletric-Power Generation, Massachusetts Institute of Technology
Laboratory: Wright Laboratory
Date of Publication: 1991-08
Pages: 20
Contract: Laboratory Research - No Contract
DoD Project: 2401
DoD Task: 240104
Identifier: This paper is part of a conference proceedings. See ADA241311
Abstract:
Statistical Energy Analysis (SEA) techniques are used to analytically determine the damping effect achieved by attaching a quantity of mass-dampers to a damped flat plate. Mass-dampers are defined as SDOF oscillators which are over damped and have a resonant frequency below the frequency range of interest. The analysis has shown that the damping effect achieved by this approach is maximized when damper impedance is matched to a particular ratio of the average drive point impedance of the plate. The analysis indicates that the damping effect achieved is significant for mass-damper mass to plate mass ratios as low as 0.05 to 0.2. A prototype mass-damper system was designed and tested to verify the analytical results. The experimental results showed that significant improvements in damping were achieved and that the amplitude of modal frequencies were reduced by as much as 10-15 dB over a wide frequency range. This approach differs from visco-elastic techniques in that it does not share strain energy with base structure. This characteristic may make this approach ·effective for damping stiff structures at low frequencies.