MODELING RELAXATION BEHAVIOR OF YARNS .1. EXTENDED, NONLINEAR MAXWELLMODEL

A theoretical model for the description of relaxation curves after dyn amic loading is presented in this paper, The model is based on a nonli near spring placed in parallel with Maxwell elements. The obtained for mula is fitted on experimental relaxation curves using the Marquardt-a lgorithm for nonlinear regression, Relaxation curves can be classified into ordinary relaxation, mixed relaxation and inverse relaxation cur ves, There seems to be good correspondence between the experimental an d the fitted relaxation curves.