Deformation Behaviors of Auxetic Warp Knitted Fabrics Based on Reentrant Geometry

Abstract

A series of auxetic warp knitted fabrics based on reentrant geometry were developed in our previous study and their Poisson's ratio in the wale direction and course direction can be as low as −0.5 and −0.15, respectively. However, the quantitative relationships between structural parameters and auxetic effect, which can offer a guide to the design and manufacture process, are still unknown. Herein, the aim is to find such relationships. Based on the geometrical analysis, two semiempirical equations between Poisson's ratio and tensile strain are established when stretched in the wale direction and course direction, respectively. The study shows that the established semiempirical equations fit well with experimental results and can be used to predict auxetic effect of fabrics made with the same type of materials and similar structures. With the relationships proposed, warp knitted fabrics can be designed and manufactured directly without trials to obtain the desired auxetic effect, which can largely save the time and cost of production.

Auxetic structures used in kinesiology tapes can improve form-fitting and personalization

“…The current auxetic prototypes were fabricated using a 3D printing technology that does not allow the manufacturing of such rolls. Further fabrication techniques could be explored, such as the manufacturing of auxetic fabrics or auxetic yarn 45 , 46 . On one side of the auxetic fabric, an acrylic adhesive should be applied to guarantee the proper attachment to the skin.…”

A Novel Barbell‐Shaped Perforated Auxetic Metastructure with Superior Auxetic Effect

“…The counterintuitive NPR effect can reportedly enhance the mechanical properties of auxetic metastructures in a variety of aspects, e.g., elastic constants, indentation, crushing, acoustic, wave propagation, energy absorption, fatigue, and fracture. [ 5–25 ] Benefiting from these properties, auxetic metastructures can be widely used in various fields, such as textile, [ 26–28 ] biomedicine, [ 29–31 ] aerospace, [ 32–34 ] military, [ 35–37 ] and civil engineering. [ 6,12,38–40 ]…”

“…The counterintuitive NPR effect can reportedly enhance the mechanical properties of auxetic metastructures in a variety of aspects, e.g., elastic constants, indentation, crushing, acoustic, wave propagation, energy absorption, fatigue, and fracture. Benefiting from these properties, auxetic metastructures can be widely used in various fields, such as textile, [26][27][28] biomedicine, [29][30][31] aerospace, [32][33][34] military, [35][36][37] and civil engineering. [6,12,[38][39][40] As the first man-made auxetic metastructures were proposed by Lakes in 1987, [41] various forms of auxetic metamaterials have been designed and fabricated by numerous researchers in the fields of materials science and mechanics.…”

Deformation behavior of auxetic laminated fabrics with rotating square geometry

“…According to the monographs, 8–10 typical auxetic structures include reentrant cells, rotating polygons, folded structures, nodule fibril models, missing rib models, chiral and anti-chiral lattices, egg rack structure, etc. Those that have been adopted in knitted or woven fabric designs are mainly folded structures, 11–16 rotating rectangles, 12,17 rotating hexagons, 18–21 reentrant hexagons, 17,22–28 and reentrant triangles. 29 Developing auxetic fabrics directly through existing yarn materials and textile formation techniques has always been the end goal of researchers.…”

“…lattices, egg rack structure, etc. Those that have been adopted in knitted or woven fabric designs are mainly folded structures, [11][12][13][14][15][16] rotating rectangles, 12,17 rotating hexagons, [18][19][20][21] reentrant hexagons, 17,[22][23][24][25][26][27][28] and reentrant triangles. 29 Developing auxetic fabrics directly through existing yarn materials and textile formation techniques has always been the end goal of researchers.…”