Resonance phenomena in oscillatory shear rheometry: Influence of material parameters

Beitrag bei einer Tagung
(Abstract zum Poster)


Details zur Publikation

Autor(en): Redel M, Walter B, Kaschta J, Schubert DW
Jahr der Veröffentlichung: 2018


Abstract

Rheological measurements are an established method for the
characterisation of dynamic mechanical polymer properties. In current
literature, possible restrictions to thesemeasurements by the phenomenon
of resonance were evaluated by Stettin [1]. However, this paper is
quiet about the influence of material parameters like stiffness or
damping on the resonance phenomenon Therefore, an unfilled silicone
elastomer, free of material particle interactions, is used. The
cylindrical specimen are cured in a rheometer binding them firmly to the
rotor. This has proven to prevent occurrence of for example wall slip
[2].

The experiments conducted are frequency sweeps by means of a
parallel-plate rheometer with a smooth geometry surface. Consequently,
the influence of the setup, which was detected by Stettin [1], can be
neglected. Resulting resonance frequencies are analysed concerning the
material's damping and stiffness. Change in these parameters is realised
by variation of mixture as well as addition of an additive. The
resulting resonance frequencies show an explicit dependency of complex
shear modulus |G*| as a measure of the stiffness. The resulting
dependence in double logarithmic plot is compared with resonance
frequency calculations based on oscillatory theories. Contribution of
varying damping, realised by changing loss factor tan(δ), is detectable
as an additional shift in resonance frequency and also discussed.

Intriguingly,
the wavedata of the stress response after resonance, obtained via fast
Fourier transformation, differs from the expected sinusoidal signal. The
change in wavedata and aberration from the sinusoidal excitation is
explained by the phenomenon of vibration isolation. Furthermore, it is
correlated with the material’s parameters reasoning the different
experimental outcomes caused by the change in composition. A guideline
to avoid the influence of resonance on oscillatory measurements is
lastly presented.


FAU-Autoren / FAU-Herausgeber

Kaschta, Joachim Dr.-Ing.
Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe)
Redel, Michael
Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe)
Schubert, Dirk W. Prof. Dr.
Lehrstuhl für Werkstoffwissenschaften (Polymerwerkstoffe)
Walter, Bastian
Lehrstuhl für Technische Mechanik


Zitierweisen

APA:
Redel, M., Walter, B., Kaschta, J., & Schubert, D.W. (2018). Resonance phenomena in oscillatory shear rheometry: Influence of material parameters. Poster presentation at Nordic Polymer Days 2018, Kopenhagen, DK.

MLA:
Redel, Michael, et al. "Resonance phenomena in oscillatory shear rheometry: Influence of material parameters." Presented at Nordic Polymer Days 2018, Kopenhagen 2018.

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Zuletzt aktualisiert 2018-11-08 um 02:23