Concerning the Theory of Fatigue Failure in Textile Materials

Abstract

A minor modification of the reaction rate theory of flow is proposed with the aim of accounting, in terms of molecular processes, for the observed dependence of dynamic properties, particularly fatigue, on the frequency of stressing. To this end a factor ϕ ( v). which is a function of the frequency v. is introduced into the expression for the rate of breakage of bonds in the macromolecules of textile materials. It is shown that with this reasonable assumption of a frequency factor there results a general expression which, like earlier expressions, is compatible with the known dependence of fatigue life on tem perature and stress under dynamic as well as dead loads. The present development goes further, permitting the derivation of a specific expression which is in accord with the ob served frequency dependence of the fatigue life of a textile material.