Geometrical modeling of honeycomb woven fabric architecture

Honeycomb woven fabric is considered as a single layer fabric produced only using common weaving looms, but it forms a unique three-dimensional (3D) architecture with inverted pyramidal pits on the fabric surface and repeated tetrahedral-closed space inside the fabric, which is greatly different from the traditional 3D woven fabrics, such as angle-interlock and orthogonal fabrics, showing good prospect for various applications in fields such as geotextiles, medical textiles, air filter, tower packing and underclothing. This paper proposes an analytical model to characterize the geometrical shape and position of each yarn in a honeycomb fabric unit-cell and the volume of the internal space. The model is based on the assumption of fabric thickness in the sum of yarn height and the linear relationship of yarn position and fabric unit-cell dimensions. The model involves geometric parameters, including yarn width, height, spacing, crimp and the number of yarns in a fabric unit-cell. Six honeycomb woven fabrics were manufactured to verify the model. Based on the position and crimp prediction of each yarn node, the architectures of the six fabrics were simulated numerically, which shows close agreement with the observed manufactured fabrics, indicating good accuracy of the geometrical model. A sensitivity study shows that the volume of the internal space decreases with the increase of fabric density, and the application of the elastic yarns to the fabric reduces the volume significantly.