Stress-Strain Relationships in Yarns Subjected to Rapid Impact Loading

Abstract

If a textile yarn segment, clamped at each end, is impacted transversely at the mid point, the stress-strain curve for this yarn can be obtained from measurements on a high speed photographic record of the yarn's motion. This paper describes the apparatus and procedure used. Stress-strain curves for high rates of straining, of the order 5000%/sec., obtained by this method are given for high tenacity nylon, Fortisan, and Fiberglas. Comparison with stress-strain data obtained at conventional rates shows that these mate rials have higher initial moduli, and that their stress-strain curves remain linear up to higher stress values, when the testing rate is high. The breaking tenacities are slightly greater and breaking elongation slightly smaller at these high test rates.

Transverse Impact Response of a Linear Elastic Ballistic Fiber Yarn

“…They tried to obtain the stress-strain relationship in a fiber yarn through transverse impact testing because of immature dynamic experimental techniques for obtaining the stress-strain response six decades ago. Both experiments and theoretical analyses were conducted [11][12][13]. Similar analyses have also been conducted by Vinson and Zukas [14] and Roylance et al [15,16].…”

“…The transverse impact response of a single fiber yarn has been investigated, both analytically and experimentally, since the 1950s [9][10][11][12][13][14][15][16][17]. Cole et al [10] developed a nonlinear theory for constant-strain waves in elastic strings subjected to transverse impact.…”

“…However, no experimental result was presented to support their analysis. Since the late 1950s, Smith and his colleagues [11][12][13] conducted a series of comprehensive research on the transverse response of a fiber yarn subjected to impact loading. They tried to obtain the stress-strain relationship in a fiber yarn through transverse impact testing because of immature dynamic experimental techniques for obtaining the stress-strain response six decades ago.…”

Dynamic behaviour of silks: Nature’s precision nanocomposites

“…2, leaves us with the relation shown in Eq. (1), derived by Smith [10]. The distances travelled by the projectile velocity, V, and measured transverse wave velocity, C W , form the sides of the triangle, and the length of material that has flowed past the transverse wavefront forms the hypotenuse.…”

“…However, being fibrous in form, silks are good candidates for a classical ballistic-impact experiment, devised by J. C. Smith and colleagues for use on textile yarns [10]. Transverse impact at moderate velocity produces both longitudinal and transverse waves in a fibre, the latter of which is easily recorded using a high-speed camera.…”