A Study on the Characteristics of Vibration Damping of a Beam with Inserted Viscoelastic Layer

점탄성층을 삽입한 3층 적층보의 진동감쇠특성에 관한 연구

  • 박응순 (명지대학교 대학원 기계공학과) ;
  • 박세만 (명지대학교 기계공학과) ;
  • 박명균 (명지대학교 기계공학과) ;
  • 박상규 (연세대학교 산업환경공학과)
  • Published : 1997.06.01

Abstract

For a number of years it has been known that flexural vibration in a beam and plate can be damped by the application of layer of damping (viscoelastic) material that is in turn constrained by a backing layer or foil. In this study, a quantitative analysis of damping of the sandwich beam has been performed by using impact test. The damping is characterized by the loss factor .etha. in which the damping is normalized by imaginary part of the complex bending stiffiness of the beam. Results show that the relative thickness of the sandwich beam gives more effect on the riatural-frequencies and loss factor than the variation of width does. It is also shown that the Ross-Kerwin-Ungar equation and impact test can be effectively used to identify the damping characteristic of the sandwich beam and viscoelastic material.

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References

  1. Acustica,Akustische Beihefte v.2 no.4 Uber die Damping der Biegeschwingungen dunner Blech, durch fest haftende Blelage H. Oberst
  2. Journal of the Acoustic Society of America v.31 no.7 Damping of Flexural Waves by a Constrained viscoelastic Layer Kerwin, Edward M. Jr.
  3. Journal of the Acoustic Society of America v.34 no.8 Loss Factor of Viscoelasticically Damped Beam Structures Ungar, Eric E.
  4. Journal of Applied Mechnics;Trans. ASME, Series E v.32;88 no.4 Theory of Vibratory Bending for Elastic Viscoelastic Layered Finite Length Beams DiTaranto, R. A.
  5. Journal of Sound and Vibration v.10 no.2 The Forced Vibration of a Three-Layer, Damped Sandwich Beam with Arbitrary Boundary Conditions Mead, D. J.;Markus, S.
  6. Structural Damping Damping of Plate Flexural Vibration by Means of Viscoelastic Laminate D. Ross;E. E. Ungar;E. M. Kerwin, Jr.
  7. Vibration Damping Ahid D. Nashif;David I. G. Jones;John P. Henderson
  8. Sound and Vibration Understanding Vibration Measurements G. F. Lang
  9. Measurements of Damping for Nondestructively Assessing the Integrity of Fiber Reinforced Composites Bai-Tang Lee
  10. Sound and Vibration Impulse Technique for Structural Frequency Response Testing W. G. Hslcorsen;D. L. Brown