Title:Measurement of Viscoelastic Properties by Free Loading-Mass Method
Volume: 1
Author(s): Kulik V.M.*
Affiliation:
- Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
Keywords:
Measurement method, viscoelastic properties, one-dimensional model, two-dimensional model, poison’s ratio, resonance.
Abstract:
Background: A procedure for determining the elastic and viscous properties of the
sample material on the basis of the forced vibrations of a sample of mass m loaded with a certain
mass M is developed. One of advantages of using the top mass instead of a rigid fixation is the
appearance of an additional deformation resonance, the frequency of which is π √ M / m times
smaller than the resonance frequency of the fixed sample.
Method: The experimental setup implementing the free mass method is described. Notably, the
proposed scheme does not require any adjustment and is assembled from standard devices. By
changing the design of the sample only, both shear and compression-tension strains can be measured.
The combination of these methods allows measuring the complex Poisson’s ratio, in addition
to modulus of elasticity and loss factor.
Results: One-dimensional (1D) and two-dimensional (2D) models of specimen deformation are
considered. For the 1D deformation model, approximate formulas for calculating the modulus of
elasticity and the loss factor are substantiated and the limits of validity these formulas are outlined.
Improving the accuracy of measurements is also considered. To do this, it is necessary to
fully describe the boundary conditions on the deformable sample. The developed 2D model of
sample deformation made it possible to calculate the elastic modulus form factors for various
samples with axial symmetry.
Conclusion: The method may become a Standard for measuring viscoelastic properties of materials
(complex elastic and shear modulus, as well as complex Poisson's ratio).
