Porosity prediction of plain weft knitted fabrics

Wearing comfort of clothing is dependent on air permeability, moisture absorbency and wicking properties of fabric which are related to the porosity of fabric. In this work a plug-in is developed using Python script and incorporated in Abaqus/CAE for the prediction of porosity of plain weft knitted fabrics. The Plug-in is able to automatically generate 3D geometrical models and accurately determine the porosity of fabrics in three steps. In this work plain weft knitted fabrics made of monofilament, multifilament and spun yarn made of staple fibers were used to evaluate the effectiveness of the developed plug-in. In case of staple fiber and multifilament yarn intra yarn porosity was considered in the calculation of porosity. The first step is to develop a 3D geometrical model of plain weft knitted fabric, the second step is to mesh the generated fabric geometry in step one, and the third step is to calculate the porosity of the fabric by using so called finite element analysis. The predicted porosity of plain weft knitted fabric extracted from the output database (odb file) in the third step is displayed in the message area when post-processing analysis completed. The predicted results obtained from plug-in have been compared with the experimental results obtained from previously developed model. They are agreed well. Furthermore a plug-in is developed to generate the multifilament weft knitted fabric by using idealized packing of circular fibers in yarn.