Bending vibrational properties of fabrics. II. A theoretical model of fabric bending vibration and its analysis

In order to clarify the mechanism of the inter-yarn and/or inter-fiber frictional effect during bending vibration of fabrics, a model of fabric bending vibration was proposed. The model was studied using the samples having different degree of weft yarn density and yarn twist and following conclusions were obtained. (1) A theoretical equation for the amplitude decrease in the 1st step of bending vibration was derived. (2) Parameters of amplitude decrease; Δd1, Δd2 increase and those of duration period; S1, S2 decrease with the increase of weft yarn density. Existence of the effect of yarn contacting length and contacting pressure on bending vibration was clearly shown. (3) Effect of twist was different with yarn type; filament or spun, the effect on bending vibration was large. Existence of contacting factor was shown.