Standard Test Method for Dynamic Young's Modulus, Shear Modulus, and Poisson's Ratio by Impulse Excitation of Vibration 1

TLDR

The ISO standard E 1876, with its designation and revision year indicators, establishes the framework for measuring dynamic elastic properties, noting that specimen resonant frequencies depend on modulus, mass, and geometry. The test method aims to determine the dynamic Young’s modulus, shear modulus, and Poisson’s ratio of elastic materials at ambient temperatures. It computes these properties by measuring the geometry, mass, and resonant frequencies of a rectangular or cylindrical specimen, using flexural or longitudinal vibration for Young’s modulus and torsional vibration for shear modulus, and allows for temperature adjustments with appropriate modifications. Dynamic Young’s modulus and shear modulus obtained by this method enable calculation of Poisson’s ratio. Reference 1.

Abstract

This standard is issued under the fixed designation E 1876; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 This test method covers determination of the dynamic elastic properties of elastic materials at ambient temperatures. Specimens of these materials possess specific mechanical resonant frequencies that are determined by the elastic modulus, mass, and geometry of the test specimen. The dynamic elastic properties of a material can therefore be computed if the geometry, mass, and mechanical resonant frequencies of a suitable (rectangular or cylindrical geometry) test specimen of that material can be measured. Dynamic Young’s modulus is determined using the resonant frequency in either the flexural or longitudinal mode of vibration. The dynamic shear modulus, or modulus of rigidity, is found using torsional resonant vibrations. Dynamic Young’s modulus and dynamic shear modulus are used to compute Poisson’s ratio. 1.2 Although not specifically described herein, this test method can also be performed at cryogenic and high temperatures with suitable equipment modifications and appropriate modifications to the calculations to compensate for thermal expansion.