Fatigue Fracture Morphology of Nylon Filaments

Abstract

The fatigue fracture morphology of two nylon filaments (mono and 3-ply) have been inves-tigated.
Photographs of tensile fracture indicate that the two nylons show a similar straight fracture across the fiber axis. However, in fatigue fracture morphology, two typical kinds of morpho-logical feature are obtained.
In monofilament, fatigue fracture is developed along the fiber axis, showing longitudinal splitting (long tail-like rupture end). While in 3-ply filament, the fracture occurs across its axis, showing a plain rupture end.
It is suggested that the two types of fracture morphology reflect the different fracture mechanism between the two nylons.
These causes are discussed in detail in order to understand the fatigue mechanism of the nylon filaments.