ORIGINAL CONTRIBUTION

Rheologica Acta

, Volume 39, Issue 2, pp 163-173

Determination of the relaxation time spectrum from dynamic moduli using an edge preserving regularization method

  • Tobias RothsAffiliated withAlbert-Ludwigs-Universität Freiburger Materialforschungszentrum Stefan-Meier-Strasse 21 79104 Freiburg im Breisgau, Germany e-mail: roths@fmf.uni-freiburg.de
  • , Dieter MaierAffiliated withAlbert-Ludwigs-Universität Freiburger Materialforschungszentrum Stefan-Meier-Strasse 21 79104 Freiburg im Breisgau, Germany e-mail: roths@fmf.uni-freiburg.de
  • , Christian FriedrichAffiliated withAlbert-Ludwigs-Universität Freiburger Materialforschungszentrum Stefan-Meier-Strasse 21 79104 Freiburg im Breisgau, Germany e-mail: roths@fmf.uni-freiburg.de
  • , Michael MarthAffiliated withAlbert-Ludwigs-Universität Freiburger Materialforschungszentrum Stefan-Meier-Strasse 21 79104 Freiburg im Breisgau, Germany e-mail: roths@fmf.uni-freiburg.de
  • , Josef HonerkampAffiliated withAlbert-Ludwigs-Universität Freiburger Materialforschungszentrum Stefan-Meier-Strasse 21 79104 Freiburg im Breisgau, Germany e-mail: roths@fmf.uni-freiburg.de

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

For the numerical determination of a continuous relaxation time spectrum from rheological data so-called regularization methods are necessary. The regularization method based on Tikhonov regularization and commonly used in rheology assumes the relaxation time spectrum to be smooth. Accordingly, this method is not able to properly resolve spectra containing edges or at least large curvatures as proposed in the literature. In order to reconstruct such spectra a novel edge preserving regularization (EPR) method was developed which extends the properties of the commonly used method. In order to demonstrate the efficiency of EPR it is compared with the commonly used regularization method by means of simulated and experimental data. This reveals that EPR is able to prove whether or not the theoretically predicted edge containing spectra for high-molecular-weight, monodisperse polymers are compatible with experimental data.

Key words Viscoelasticity Relaxation time spectrum BSW spectrum Regularization Edge preserving regularization