The definition of the mechanical properties of viscoelastic materials, i.e. the elastic modulus and the loss factor, is carried out, according to many national and international standards, with many different techniques, both of the resonant and non-resonant type. In this paper we focus our attention on the pros and cons of the resonant technique based on the classical Oberst beam method. When the damping material to be tested is not self-supporting, its properties are determined taking start from the measured modal frequencies and loss factors of a laminated beam, constituted by one or two metallic strips, ideally undamped, and one or two viscoelastic layers. The formulae specified on the standards hold valid under the assumptions of the theory developed by Kerwin, Ungar and Ross and we try in this paper to quantify witch deviation of the results should be expected when moving away from their ideal hypotheses.

Oberst beam test technique / Fasana, Alessandro; Garibaldi, Luigi; Giorcelli, Ermanno; Ruzzene, Massimo. - 3327:(1998), pp. 451-464. (Intervento presentato al convegno Smart Structures and Materials 1998: Passive Damping and Isolation tenutosi a San Diego, CA (USA) nel March 01, 1998) [10.1117/12.310708].

Oberst beam test technique

FASANA, ALESSANDRO;GARIBALDI, Luigi;GIORCELLI, Ermanno;RUZZENE, Massimo
1998

Abstract

The definition of the mechanical properties of viscoelastic materials, i.e. the elastic modulus and the loss factor, is carried out, according to many national and international standards, with many different techniques, both of the resonant and non-resonant type. In this paper we focus our attention on the pros and cons of the resonant technique based on the classical Oberst beam method. When the damping material to be tested is not self-supporting, its properties are determined taking start from the measured modal frequencies and loss factors of a laminated beam, constituted by one or two metallic strips, ideally undamped, and one or two viscoelastic layers. The formulae specified on the standards hold valid under the assumptions of the theory developed by Kerwin, Ungar and Ross and we try in this paper to quantify witch deviation of the results should be expected when moving away from their ideal hypotheses.
1998
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/1411899
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