Viscoelastic models were employed to analyze the stress-strain behavior of
cotton, acrylic, and polyester yarns. The potential model and the modified
Maxwell model gave the best fits as regards the stress-strain behavior of t
hese yarns. The results of the potential model resembled those of the modif
ied Maxwell model with an infinite relaxation time. The potential model is
suitable for explaining the rearrangement undergone by the yarns when no sl
ippage between fibers under strain occurs. When slippage occurs, Maxwell mo
dels are able to explain the stress-strain behavior of the yarns. (C) 2000
John Wiley & Sons, Inc.