Nonlinear Creep of Viscoelastic Organic Fibers under Tension.

The nonlinearity of the creep of nylon fibers is justified based on the similarity of a set of isochronous creep curves, which also includes the instantaneous deformation curve. Nonlinear hereditary constitutive equations of creep are derived. The real values of the influence function are determined as the basic rheological characteristic of the material. The applicability of Boltzmann's, Abel's, Rzhanitsyn's, and Rabotnov's kernels is estimated quantitatively. The choice of an Abel-type kernel is justified. The calculated and experimental data are in satisfactory agreement for a loading duration of up to 1,000 hours and an order of magnitude change in the stresses [ABSTRACT FROM AUTHOR]