Viscoelastic parameter determination for a yarn

Here parameter determination of a chosen rheological model of a yarn on the basis of the experimental results is shown. The Kelvin‐Voigt linear viscoelastic model of a solid material was chosen. The real yarn was used in the tear experiment. The knowledge of the stress‐strain curve is the measurement for the determination of the rheological parameter. The calculation of the Kelvin‐Voigt’s parameters, with respect to the known stress‐strain curve of the real yarn, is done with an optimisation method. In this numerical procedure the area between the response of the real yarn and the yarn model is minimised. The optimisation results show good coincidence of the real mechanical properties of the real yarn with the Kelvin‐Voigt rheological model. The model of the yarn enables simulation of real processes, which is easier because observation of the real systems are then not necessary, which is easier, more transparent and cheaper.