Journal article
Methodology for rheological testing of engineered biomaterials at low audio frequencies
The Journal of the Acoustical Society of America, Vol.115(1), pp.392-401
01/2004
DOI: 10.1121/1.1631941
PMID: 14759030
Abstract
A commercial rheometer (Bohlin CVO120) was used to mechanically test materials that approximate vocal-fold tissues. Application is to frequencies in the low audio range (20-150 Hz). Because commercial rheometers are not specifically designed for this frequency range, a primary problem is maintaining accuracy up to (and beyond) the mechanical resonance frequency of the rotating shaft assembly. A standard viscoelastic material (NIST SRM 2490) has been used to calibrate the rheometric system for an expanded frequency range. Mathematically predicted response curves are compared to measured response curves, and an error analysis is conducted to determine the accuracy to which the elastic modulus and the shear modulus can be determined in the 20-150-Hz region. Results indicate that the inertia of the rotating assembly and the gap between the plates need to be known (or determined empirically) to a high precision when the measurement frequency exceeds the resonant frequency. In addition, a phase correction is needed to account for the magnetic inertia (inductance) of the drag cup motor. Uncorrected, the measured phase can go below the theoretical limit of -pi. This can produce large errors in the viscous modulus near and above the resonance frequency. With appropriate inertia and phase corrections, +/- 10% accuracy can be obtained up to twice the resonance frequency.
Details
- Title: Subtitle
- Methodology for rheological testing of engineered biomaterials at low audio frequencies
- Creators
- Ingo R Titze - University of IowaSarah A Klemuk - University of IowaSteven Gray
- Resource Type
- Journal article
- Publication Details
- The Journal of the Acoustical Society of America, Vol.115(1), pp.392-401
- DOI
- 10.1121/1.1631941
- PMID
- 14759030
- ISSN
- 0001-4966
- eISSN
- 1520-8524
- Grant note
- 1 R01 DC04336-02 / NIDCD NIH HHS
- Language
- English
- Date published
- 01/2004
- Academic Unit
- School of Music; Communication Sciences and Disorders
- Record Identifier
- 9984719567102771
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