Resonant Ultrasound Spectroscopy
Resonant Ultrasound Spectroscopy
Elastic constants such as the Young's modulus, Poisson's ratio, or the components of the elastic tensor are of fundamental importance, for example, for industrial applications and understanding the function of biological materials. These constants can be measured non-destructively using Resonant Beam Technique (RBT) or Resonant Ultrasound Spectroscopy (RUS). In these methods, the natural frequencies of the sample are first determined experimentally. The second step starts with a suitable set of elastic constants that would be typical for the sample material and aligns (or "fits") the calculated natural frequencies to the measured natural frequencies by appropriately modifying the elastic constants. If sufficient agreement between the measured and calculated natural frequencies can be achieved, then the elastic constants correspond to the constants of the sample.
Overview of application possibilities
- Measurement of the elastic constants of isotropic beams or cylinders whose length is ≥ 10 * width/height/diameter, using the Resonant Beam Technique.
- Measurement of the elastic constants of isotropic and anisotropic spheres, cuboids, or cylinders whose three dimensions are of a similar order of magnitude, using Resonant Ultrasound Spectroscopy.
Contact Person
Puchegger, Stephan
Head
Währinger Straße 38-42
1090
Wien
Room: 3342
Email
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+43-1-4277-73802
Terms of use and usage fees
The RBT/RUS measuring station cannot be used autonomously. Measurements are possible subject to the availability of the contact person. Please get in touch if you are interested in measurements to clarify the suitability of the samples for this method. Samples must be homogeneous and manufactured with sufficient precision to allow their properties to be accurately represented by the theory.
| User group | Measurement fee for the first sample of a type / each additional sample |
|---|---|
| Faculties of Physics and Chemistry | - |
| Vienna Life Science Instruments | 100 € / 50 € |
| University users | 200 € / 100 € |
| Non-university users | upon request |
References
- RBT
- W. Lins, G. Kaindl, H. Peterlik, K. Kromp, A novel resonant beam technique to determine the elastic moduli in dependence on orientation and temperature up to 2000°C – doi: 10.1063/1.1149867
- RUS
- B. J. Zadler, J. H. L. Le Rousseau, J. A. Scales, M. L. Smith, Resonant Ultrasound Spectroscopy: theory and application – doi: 10.1111/j.1365-246X.2004.02093.x
- I. Ohno, Free Vibration of a Rectangular Parallelepiped Crystal and its Application to Determination of Elastic Constants of Orthorombic Crystals – doi: 10.4294/jpe1952.24.355
- H. H. Demarest, Cube‐Resonance Method to Determine the Elastic Constants of Solids – doi: 10.1121/1.1912415
- E. Mochizuki, Application of Group Theory to Free Oscillations of an Anisotropic Rectangular Parallelepiped – doi: 10.4294/jpe1952.35.159
Are my samples suitable for RUS or RBT?
Since both techniques compare measured eigenfrequencies with calculated eigenfrequencies, the samples must be as ideal as possible. This means they must be homogeneous and manufactured with low tolerances. If the samples consist of, for example, a porous material, the sample needs to be large compared to the size of the pores to allow the sample to be represented as a continuum.
As mentioned above, the sample forms are limited by the forms available in the respective theory:
- RBT: Beams and cylinders whose length is ≥ 10 * width/height/diameter, since the theory is based on the assumption of a long sample.
- RUS: Cuboids and cylinders whose three dimensions are of similar orders of magnitude, and spheres.
The available theories also partially limit the possible elastic symmetry:
- RBT: The fundamental theory is one-dimensional and only works well for isotropic materials. Anisotropic samples are theoretically possible up to orthorhombic symmetry, but this requires multiple samples cut from the specimen body in different directions. Such an analysis is also very time-consuming.
- RUS: The theory is anisotropic. However, the more complex the elastic symmetry, the more perfect the sample has to be, and the approximate elastic constants must be known beforehand. Fitting the calculated eigenfrequencies to the measured eigenfrequencies is a hopeless endeavor without good starting values.