Finite Element Modeling of Auxetic Warp-Knitted Fabric Made of Re-entrant Geometry

Auxetic fabrics are those with a negative Poisson's ratio and have received increasing attention in recent years. In our previous study, a series of auxetic warp-knitted fabrics were developed based on re-entrant geometry and their auxetic effects were experimentally investigated. Unlike weft-knitted fabrics, the preparation and production process of warp-knitted fabrics are very complicated and time consuming. However, finite element (FE) method offers an efficient way to simulate and predict their auxetic behavior without conducting the manufacturing process and experimental tests. Herein, an FE study of auxetic warp-knitted fabric structures is conducted. The FE models are established from the geometry of a real fabric and compared with the experimental results. It is shown that the variation trends of Poisson's ratio agree well between the simulation and experiment. Although simulation results are slightly different from the experimental ones, it still proves feasible for predicting auxetic effects of auxetic fabrics using the FE models. It is expected that this research can offer a useful method to model and simulate the deformation behavior of auxetic warp-knitted fabrics, providing a guide for the design and development of more novel auxetic fabric structures.