Abstract
It is well known that the relaxation spectrum characterizing the linear viscoelastic properties of a polymer melt or solution is not directly accessible by an experiment. Therefore, it must be calculated from data for a material function. With Tikhonov regularization the relaxation spectrum in the terminal and plateau region can be calculated from data for a material function in the corresponding region. Serious difficulties arise however, if the spectrum should be determined in a larger range. These difficulties are caused by the considerably different contributions at short and long relaxation times. We show that these difficulties can be avoided by a nonlinear regularization method.
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Honerkamp, J., Weese, J. A nonlinear regularization method for the calculation of relaxation spectra. Rheologica Acta 32, 65–73 (1993). https://doi.org/10.1007/BF00396678
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DOI: https://doi.org/10.1007/BF00396678