VISCOELASTIC STUDIES OF TEXTILE FABRICS: (VI) ANISOTROPY OF THE STIFFNESS OF TEXTILE FABRICS

(1) The stiffness of textile fabrics depends upon its bending directions, and in general the stiffness in bias directions is relatively small. (2) In so far as the bending is concerned, the fabrics are like 2-plywood but when woven into typical ribs in one direction they become like in mono-plywood. (3) The stiffness in any directions may by expressed as following, (EI)θ=(EI)w sin4θ+(EI)F cos4θ where, (EI)w and (EI)F are flexible rigidity in the warp and weft ways respectively, and θ the angle with the warp. The mean value of EI in any directions (EI)m=3/8{(EI)w+(EI)F} It is imossible to apply this simple formula to all kinds of fabrics. In general the balanced plain clothes is governed by this formula.