Continuous measurement of apparent Poisson’s ratio for yarn based on omni-directional diameters

Abstract

We proposed a new method of measuring apparent Poisson's ratio for yarn and developed a new tensile tester equipped with a digital micrometer that can measure the yarn's omni-directional diameter annularly while the yarn is elongated. Values of apparent Poisson's ratio were obtained from the longitudinal and transverse strains continuously. The mean diameter measured omnidirectionally was used to calculate the transverse strain for each longitudinal strain. We tested five spun yarns, one mono filament yarn and two filament yarns and obtained values of apparent Poisson's ratio against longitudinal strain for all samples. Apparent Poisson's ratio was not constant for spun and filament yarns while it was constant for monofilament yarn. When the longitudinal strain was low, apparent Poisson's ratios of ring spun yarns and filament yarns were large owing to the fiber packing density. As the longitudinal strain increased, apparent Poisson's ratio gradually decreased. Furthermore, we approximated the relationship between apparent Poisson's ratio and the longitudinal strain using a power function. The apparent Poisson values can be used in the simulation of fabrics.

Variation of Poisson’s ratio of fabrics woven with helical composite auxetic weft yarns in relation to fabric structural parameters

“…A modified version of the method proposed in Takatera et al. [20] was used to measure the Poisson’s ratio of yarn components. The reported values of Poisson’s ratio are average of three measurements.…”

“…Physical and mechanical characteristics of the auxetic yarn components and the HAY are shown in Tables 1 and 2, respectively. A modified version of the method proposed in Takatera et al [20] was used to measure the Poisson's ratio of yarn components. The reported values of Poisson's ratio are average of three measurements.…”

Longitudinal compression and Poisson ratio of fiber yarns in meso-scale finite element modeling of composite reinforcements

“…Some studies have been carried out to determine the Poisson ratio of fiber yarns. They concern the transverse strains of yarns under tension [30][31][32][33][34]. Some of these investigations have dealt with auxetic yarns, i.e., yarns with negative Poisson ratios [31][32][33].…”

Measurement of torsional rigidity of yarns with different crimps

“…The cotton yarn samples were made by ring spinning using the same combed cotton roving. The average diameter of cotton spun yarn was obtained using a digital micrometer (Keyence Corporation, LS7000, measurement accuracy ± 0.5 µm) at an angle from 0° to 180° [18]. The yarn setting conditions are shown in Table 2.…”

“…The average diameter of cotton spun yarn was obtained using a digital micrometer (Keyence Corporation, LS7000, measurement accuracy AE 0.5 mm) at an angle from 0 to 180 . 18 The yarn setting conditions are shown in Table 2. The suffix refers to the diameter of the rods.…”