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Mechanical Impedance Based Vibration Damping Test
ISSN: 0148-7191, e-ISSN: 2688-3627
Published June 05, 2017 by SAE International in United States
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Traditionally, the damping performance of a visco-elastic material is measured using the Oberst bar damping test, where a steel bar is excited using a non-contacting transducer. However, in an effort to reduce the weight of the vehicles, serious effort is put in to change the body panels from steel to aluminum and composite panels in many cases. These panels cannot be excited using a non-contacting transducer, although, in some cases, a very thin steel panel (shim) is glued to the vibrating bar to introduce ferrous properties to the bar so it can be excited. In the off highway vehicles, although the panels are made of steel, they are very thick and are difficult to excite using the Oberst bar test method. This paper discusses a measurement methodology based on mechanical impedance measurements and has the potential to be a viable/alternate test method to the Oberst bar testing. In the impedance method, the test bar is mounted to a shaker at the center (Center Point method). The damping performance is measured from the frequency response function obtained from the excitation force and the corresponding velocity level, both measured at the same point.
CitationSaha, P., "Mechanical Impedance Based Vibration Damping Test," SAE Technical Paper 2017-01-1879, 2017, https://doi.org/10.4271/2017-01-1879.
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- Ross, D., Ungar, E. E., Kerwin, E. M., Jr., “Damping of Plate Flexural Vibrations by Means of Viscoelastic Laminate,” Structural Damping, ASME New York, Section 3, pp 49-87, 1959.
- Chahine, J. and Saha, P., "Rationale for a Standardized Vibration Damping Test Procedure for Automotive Applications," SAE Technical Paper 920406, 1992, doi:10.4271/920406.
- SAE International Surface Vehicle Recommended Practice, “Laboratory Measurement of the Composite Vibration Damping Properties of Materials on a Supporting Steel Bar,” SAE Standard J1637, Iss. Feb. 1993.
- Saha, P. and Myers, R., "Importance of Sealants for Interior Noise Control of Automobiles," SAE Technical Paper 920412, 1992, doi:10.4271/920412.
- SAE International Surface Vehicle Recommended Practice, “Laboratory Measurement of the Composite Vibration Damping Properties of Materials on a Supporting Steel Bar,” SAE Standard J1637, Rev. June 2013.
- Japanese Standards Association, “Test Methods for Vibration-Damping Property in Laminated Damping Steel Sheets of Constrained Type,” JIS G 0602:1993.
- ISO Standard, “Glass in Building - Glazing and Airborne Sound Insulation-Measurement of the Mechanical Impedance of Laminated Glass,” ISO 16940:2008.
- Wojtowickia, J-L., Jaouen, L., and Panneton, R., “New Approach for the Measurement of Damping Properties of Materials Using the Oberst Beam,” Review of Scientific Instruments, American Institute of Physics, Vol. 75, No. 8, Aug. 2004, doi:10.1063/1.1777382.
- Dowling, J. and Saha, P., "A Correlation between Oberst Bar and Center Point Damping Results," SAE Technical Paper 2009-01-2134, 2009, doi:10.4271/2009-01-2134.
- Malogi, D., Gupta, A., and Kathawate, G. R., “Center Impedance Method for Damping Measurement,” Hindawi Publishing Corporation, Advances in Acoustics and Vibration, Volume 2009, Article ID 319538, doi:10.1155/2009/319538.
- Stanley, D. R., “Alternative Method of Measuring System Loss Factor,” presented at the NOISE-CON 2014, Fort Lauderdale, FL, September 8-10, 2014.
- ASTM International, “Standard Test Method for Measuring Vibration-Damping Properties of Materials”, ASTM E-756-05(2010).