There are now different kinds of geometrical models for auxetic materials, such as re-entrant model, rotating model, nodule and fibril model, chiral model, liquid crystalline model, helical model and rod model for describing the angle-ply composites. Knitting technology, including plane and 3D warp knitting as well as weft knitting, is widely used in the manufacturing fields nowadays and has been adopted in fabric structure designing. Knitted fabrics with negative Poisson’s ratio have great potentials in both apparel and industries. The present article reviews the auxetic principles in general and in the specific context of knitted textile structures with auxetic potential made from conventional fibers.

There are many kinds of medical textiles, such as woven textiles, non-woven textiles, braided textiles and knitted textiles. Non-woven medical textiles constitute more than 60% of the total medical textiles used, but are almost disposable ordinary medical textiles. While knitted fabrics forms a small part of the medical textiles, but are greatly applied in high-tech medical textiles, containing artificial blood vessels, hernia patches, cardiac support devices, knitted medical expandable metallic stents and tendon scaffolds. Knitting structures, including weft knitting structure and warp knitting structure. The knitted textiles are popular for their loose structure, greater flexibility, higher porosity, more flexible structure and better forming technology. The present article will introduce some knitting structures and materials applied in the medical textiles in accordance with non-implantable, implantable, extra-corporeal textiles and healthcare and hygiene products.

This paper compares the ballistic impact damage behaviors between the three-dimensional angle-interlock woven fabric and its reinforced composite (three-dimensional angle interlock woven composite) under various ballistic strike velocities based on experimental and numerical finite element analysis. In experiments, the residual velocities of projectiles were recorded to compare their ballistic proof properties undergoing different impact loading conditions. Furthermore, the ultimate damage morphologies of both types of materials were also compared to deduce the specific ballistic impact performance and energy absorption mechanisms between the three-dimensional angle interlock woven fabric and three-dimensional angle interlock woven composite. It was found that the three-dimensional angle interlock woven composite has absorbed more energy than the three-dimensional angle interlock woven fabric under the “high” ballistic velocities (higher than 350 m/s). And it shows the opposite phenomena under the “low” ballistic velocities (lower than 350 m/s). In finite element analysis, the simplified finite element models were established for both materials to characterize the critical importance of resin matrix in transferring and dissipating the high velocity impact energy. Especially for three-dimensional angle interlock woven composite, the impact energy was transferred to the large area during a relatively short period of time, thereby resulting in an overall bearing capacity of the composite structure, therefore absorbed most of the impact energy, which was well applied to explain the experimental results.