Abstract:

For more real simulation effects and enrichment of details of weft knitted fabric geometry, this paper models the fabric at the scale of fibers. A three-layer spiral fiber structure of twisted yarn model was established for yarn geometry of weft knitted fabric. Rotation minimizing frames were regards as local coordinates for calculating fibers positions. A yarn model was established based on the methods of geometric and coordinate transformation, which had arbitrary curved center line. According to three basic knitted fabric structure of knit, tuck and float, three typical structure units of weft knitted fabric were constructed with non-uniform rational B-Splines, which were obtained with calculated control points. Finally, an algorithm for building a geometric model of weft knitted fabric using twisted yarns based on the structural notation was proposed. A sample using the algorithm was shown. The geometric model of weft knitted fabric with twisted yarn established according to the algorithm in this paper has remained details of yarn twisting, which looks closer to the real fabric.

Key words: weft knitted fabric, model of twisted yarn, geometric model, weft-knitted structure