Damping mechanisms and phenomenology in materials
Definition of damping. Sensitive Theological measurements reveal that perfect elasticity is almost never observed in materials and structures even at low stress. Under cyclic loading inelasticity leads to a stress-strain relation that is not a single-valued function but instead forms a hysteretic loop (see Fig. 1 and Table 1). The area within the loop is proportional to the energy dissipated per cycle of loading, a property identified by the term “damping” or “internal friction” in this paper. This definition of damping specifically excludes energy transfer devices such as dynamic absorbers or so-called dynamic “dampers”; energy must be absorbed within the specified system before the term damping is applicable.
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- American Standard Recommendations for Nomenclature for Specifying Damping Properties of Materials, Report of ASA Committee S 2-W-33 on “Damping of Materials” American Standards Association, New York, November 1963.Google Scholar
- Lazan, B. J.: Damping of Materials and Members in Structural Mechanics. Scheduled for publication by Pergamon Press in 1965.Google Scholar
- Zener, C.: Elasticity and Anelasticity of Metals (book), University of Chicago Press, Chicago, Ill. 1948.Google Scholar
- Ferry, J. D.: Viscoelastic Properties of Polymers, John Wiley & Sons 1961.Google Scholar
- Nowiok, A. S.: Internal Friction of Metals, Progress in Metal Physics, 4, Pergamon Press 1953.Google Scholar
- Relaxation Phenomena in Metals and Alloys, edited by B. N. Finkel’shtein, authorized translation from the Russian, Consultants Bureau, New York 1963.Google Scholar
- Crandall, S. H.: On Scaling Laws for Material Damping, NASA TN D-1467, NASA, Washington, D. C., December 1962.Google Scholar
- Bishop, R. E. D., and D. C. Hohnson: The Mechanics of Vibration (book), Cambridge University Press 1960.Google Scholar
- Luecke, K., and A. Granato: Dislocations and Mechanical Properties of Crystals, John Wiley & Sons 1957.Google Scholar
- Lazan, B. J., and L. E. Goodman: Material and Interface Damping, Chapter 36, Shock and Vibration Control Handbook, edited by C. M. Harris and C. E. Crede, New York: McGraw-Hill 1961.Google Scholar
- Coohardt, A.: Magnetomechanical Damping, Chapter 11 in book Magnetic Properties of Metals and Alloys, Amer. Soc. for Metals, 1959.Google Scholar