Experimental evaluation and modified Weibull characterization of the tensile behavior of tri-component elastic-conductive composite yarn

Abstract

In order to clarify the effects of the extension rate and gauge length upon the distribution of tensile strength of tri-component elastic-conductive composite yarn (t-ECCY), experimental as well as theoretical studies have been performed in this paper. Influences of the extension rate and gauge length are highlighted. The yarn exhibits an extension-rate strengthening effect, and the higher extension rate results in a higher strength and fracture strain, irrespective of the gauge length considered, and vice versa. Expressed in terms of gauge length, yarn tenacity shows a drop for a longer testing length at all extension rates, based on the weakest-link theory. A modified two-parameter Weibull strength distribution model, taking into account the effects of extension rate and gauge length, can be reasonably used to quantify the degree of variability in tensile strength and to obtain the individual Weibull parameters for practical applications. Different fracture mechanisms of the t-ECCY are demonstrated at lower and higher extension rates. A “cascade-like” break happens at lower extension rates due to inner sliding, weaker interactive transverse force of individual fibers, and sufficient time available for the fiber realignment. Nevertheless, a “chimney-like” break dominates at higher extension rates by virtue of the reduced reorientation of some disordered fibers and intensive instant impact force of the stainless steel filament component along the load direction.