Deformation behavior of auxetic woven fabric made of foldable geometry in different tensile directions

Abstract

Auxetic woven fabrics made with special geometrical structures have gained the interest of textile scientists in recent years. This paper reports a study on auxetic woven fabric based on a double-directional parallel in-phase zig-zag foldable geometrical structure. Such a fabric has been already produced and investigated for its negative Poisson's ratio effect in two principal directions (weft and warp directions). However, its negative Poisson's ratio effect in biased tensile directions as well as under repeated tensile loading conditions has not been studied yet. Therefore, in this paper, these two limitations are addressed. The auxetic woven fabric was firstly fabricated, and then subjected not only to tensile tests in different tensile directions, including two principle directions and three biased directions, but also to repeated tensile loading. It was found that both the negative Poisson's ratio effect and the resistance to tensile deformation are dependent upon the tensile direction, and the highest negative Poisson's ratio effect and higher resistance to tensile deformation are obtained in two principal directions.

Single‐ and Double‐Layered Bistretch Auxetic Woven Fabrics Made of Nonauxetic Yarns Based on Foldable Geometries

“…These properties include shear modulus, energy absorbance, vibration damping, sound absorption, indentation resistance, and synclastic behavior for better formability . The known naturally and manmade auxetic materials include metals, laminates, gels, crystalline structures, polymers, composites, foams, and textile materials including fibers, yarns, and fabrics including woven fabrics, weft‐knitted fabrics, warp‐knitted fabrics, 3D textile structure, and nonwoven fabrics …”

“…Among auxetic textile materials, auxetic woven fabrics produced by applying the technique of structural modification and made of nonauxetic yarns have gained extraordinary interest of researchers in modern times. The conventional woven fabrics have a positive PR which means that they undergo contraction in transverse direction upon stretch in the longitude direction .…”

“…In case of a garment made of conventional fabrics, the lateral contraction results in discomfort and poor shape fitting especially at joint parts . Conversely, the auxetic woven fabrics possess NPR, and they become wider in the lateral direction as well when stretched in the longitude direction . Therefore, in case of a garment made of auxetic woven fabric, the deformation of the fabric is consistent with body movements, resulting in improved comfort and shape fitting …”

“…The second technique is to fabricate auxetic fabrics from nonauxetic yarns (yarns having a positive PR) by realizing an auxetic geometry capable of inducing auxetic behavior into the fabric structure . Previously, this technique was used to produce auxetic knitted fabrics and recently was used for the development of single‐layered and double‐layered unistretch and bistretch auxetic woven fabrics . The developed auxetic‐knitted fabrics based on this technique are mostly produced on a laboratory scale because of complicated geometrical structures.…”

“…The double‐layered unistretch auxetic woven fabrics are based on foldable convexities running along the warp direction, they also have extensibility only in one direction and produced zero PR when stretched along the weft direction . Most recently, the development of single‐layered bistretch auxetic woven fabrics based on foldable geometry and re‐entrant hexagonal geometry using this technique has also been reported . These fabrics which have extensibility and auxetic behavior in both principal directions are named as bistretch auxetic woven fabrics.…”