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Erschienen in: Rheologica Acta 6/2009

01.07.2009 | Rapid Communication

Avoiding waviness of relaxation spectra

verfasst von: Joachim Kaschta, Florian J. Stadler

Erschienen in: Rheologica Acta | Ausgabe 6/2009

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Abstract

Spectra are material functions, whose different integral transforms yield the measurable rheological quantities in the linear viscoelastic regime. Therefore, their knowledge is of high fundamental interest. However, the calculation of spectra from experimental data is an ill-posed problem. Thus, it is hampered by the problem that a too low density of relaxation modes does not lead to a good description of the input data, while a higher one usually causes a wavy spectrum which cannot be interpreted. To overcome this problem, an additional criterion assuming only gradual changes in the spectrum is introduced allowing for an increase in mode density without an enhanced waviness of the spectrum. This is novel in comparison to previously published spectra algorithms and commercial software packages.

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Fußnoten
1
If the input data are more error-afflicted than in the case presented here, e.g., when using several datasets to calculate a common spectrum and thus to average the experimental data, the weighting factor has to be set to relatively high values (e.g., w f = 10).
 
Literatur
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Metadaten
Titel
Avoiding waviness of relaxation spectra
verfasst von
Joachim Kaschta
Florian J. Stadler
Publikationsdatum
01.07.2009
Verlag
Springer-Verlag
Erschienen in
Rheologica Acta / Ausgabe 6/2009
Print ISSN: 0035-4511
Elektronische ISSN: 1435-1528
DOI
https://doi.org/10.1007/s00397-009-0370-z

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