tailieunhanh - Advances in Modern Woven Fabrics Technology Part 4

Tham khảo tài liệu 'advances in modern woven fabrics technology part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Mechanical Analysis of Woven Fabrics The State of the Art 49 incompressible. Another approach based on the elastica theory including linear extensibility of the yarns was given by Dastoor et al. Dastoor et al. 1994 . They assumed the yarns to be homogeneous weightless slender rods frictionless and undeformed by shear forces. In addition the yarns were considered as having circular section which does not deform under external forces. A computational implementation was adopted for the solution of the equilibrium equations. The large biaxial deformation of partially and completely set plain woven fabrics was presented by Huang Huang 1979b Huang 1979a . His approach was based on the elastica model of yarns in the undeformed fabric and the combined action of extension and bending was considered for the fabric deformation. The introduction of bilinear moment-curvature relation due to the sliding of the fibres within the yarn in combination to the contact deformation of the yarns increases the reliability of the study. The sawtooth geometrical model was proposed by Kawabata et al. Kawabata et al. 1973 . The mechanical analysis was based on the force equilibrium and the displacement of the warp and weft yarns in the thickness direction of the fabrics at the contact point of the crossing threads. Although the geometrical representation of the unit cell was approximant the deformation effect at the cross-over points was taken into account. Most of the models described assume an unrealistic invariable cross-sectional yarn shape along the yarn path where Gong et al. Gong et al. 2010 in a recent study moves towards a more realistic representation of woven yarns suggesting an ellipse model with a variable yarn crosssectional shape based on the various parameters including fibre type yarn count yarn twist factor and cover factor. An alternative geometric model of woven fabric based on the yarns packing density as well as general fabric data has been suggested by Dolatabadi and .