Stress Relaxation of Wool Fibres in Water at Strains of 5?20 Per Cent

Abstract

A study has been made of the stress relaxation at fixed longitudinal strains of wool fibres immersed in water, in the post-yield region of their load-strain curves. The fibres were extended at controlled rates up to predetermined strains, particular attention being paid to the first few minutes of the subsequent stress relaxation. It was found that the relaxation curves so obtained could be represented by a sum of one, two, or three negative exponentials, which could, in general, be simplified into two main processes, (a) a relatively fast relaxation of stress occurring in about the first 60 sec and (b) a much slower relaxation.