Analysis of warp-knitted fabric structure. Part III: theoretical study on initial modulus of warp-knitted fabrics (reverse locknit, three- and four-needle sharkskin)

In the second part of this series, tensile properties of tricot structure were investigated. Then derived model was extended to locknit and satin as first group of fully thread two-needle bar warp-knitted fabrics. In the present study, tensile properties of second group of these warp-knitted fabrics, i.e. reverse locknit and three- and four-needle sharkskin, are considered using energy method and Castigliano’s theorem. For this purpose, the difference between the tensile properties of first and the second group of warp-knitted fabrics is attributed to the movement space and friction of back bar underlaps. Similar to previous part, free-body diagrams of elements are drawn to show the relative magnitude and direction of all forces acting upon an object in a given situation. Finally, the initial modulus of second group of warp-knitted fabrics is obtained.