Pullout test fabric deformation

FIGURE 1 Schematic of fabric deformation in yam pullout test. 

In this study the yam pullout test is applied to investigate internal mechanical properties of the plain woven fabrics. In the first step an analytical model was developed, inputs of which employs simple mechanical properties such as the fabric modtrlus, the weave angle, and the fabric deformation angles during the pullout test. This model predicts important mechanical parameters such as the weave angle variations, the yam-to-yam friction coefficient, the normal load in crossovers, the lateral forces, and the opposed yam strain within the fabric. This approach may be extended to other types of the woven fabrics. 

As a physical study, yam pullout test would be an appropriate approach to realize an estimation of the internal friction forces between the yams within the fabric. Under the circumstances of this test, a pulled yam sUdes along the intersecting perpendicular yams during fabric deformation. 

Force balance model is capable of predicting the irttemal mechanical parameters of the plain woven fabrics in a similar yam prrllout test based on the force distribution concepts. These parameters are yam-to-yam friction coef ftierrt, normal load at crossovers, lateral forces, lateral strairr, weave angle variatiorrs, arrd pullout force. Crimp angle of yams within the fabric 9 in (Figure 3)), its elastic modulus and linear density and fabric deformation data (a in (Figure 1(a))) are the required empirical factors of force balance model. The main equations of this model are presented in (Table 1) [10] ... 

Variation of crimp angle for the opposed yam due to fabric deformation by angle a during pullout test (Figure la) 0 = arctan(tan0 cos a) (7)... 

By measuring 6, in warp direction, yam linear density, and fabric deformation angle in pullout test, /tg, and of oscillation model can be computed using Equa-... 

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