Three-Dimensional Microstructural Design of Woven Fabric Composite Materials by the Homogenization Method. 1st Report. Effect of Mismatched Lay-Up of Woven Fabrics on the Strength.

The complete prediction of the second order permeability tensor for a three dimensional multi-axial preform is critical if we are to model and design the manufacturing process for composites by considering resin flow through a multi-axial fiber structure. In this study, the in-plane and transverse permeabilities for a woven fabric were predicted numerically by the coupled flow model, which combines microscopic and macroscopic flows. The microscopic and macroscopic flows were calculated by using 3-D CVFEM(control volume finite element method) for micro and macro unit cells. To avoid a checkerboard pressure field and improve the efficiency of numerical computation, a new interpolation function for velocity is proposed on the basis of analytical solutions. The permeability of a plain woven fabric was measured by means of an unidirectional flow experiment and compared with the permeability calculated numerically. Reverse and simple stacking of plain woven fabrics were taken into account and the relationship between the permeability and the structures of the preform such as the fiber volume fraction and stacking order is identified. Unlike other studies, the current study was based on a more realistic three dimensional unit cell. It was observed that in-plane flow is more dominant than transverse flow within the woven perform, and the effect of the stacking order of a multi-layered preform was negligible.

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The effects of the structural parameters of three-dimensional warp interlock woven fabrics with silver-based hybrid yarns on electromagnetic shielding behavior

Textile Research Journal ◽

10.1177/0040517519890624 ◽

2019 ◽

Vol 90 (11-12) ◽

pp. 1354-1371

Author(s):

Marzieh Javadi Toghchi ◽

Carmen Loghin ◽

Irina Cristian ◽

Christine Campagne ◽

Pascal Bruniaux ◽

...

Keyword(s):

Unit Area ◽

Structural Parameters ◽

Three Dimensional ◽

Woven Fabrics ◽

Electromagnetic Shielding ◽

Woven Fabric ◽

Shielding Effectiveness ◽

Conductive Material ◽

Conductive Yarns ◽

Multifilament Yarns

The main objective of the present study was to investigate the increase in the electromagnetic shielding effectiveness (EMSE) of a set of five variants of three-dimensional (3D) warp interlock woven fabrics containing silver multifilament yarns arranged in a 3D orthogonal grid. The EMSE enlargement as a factor of increasing the quantity of the conductive material per unit area was investigated. The quantity of the conductive material per unit area in a 3D woven fabric can be enlarged by increasing either the yarn undulation or the number of conductive yarn systems, while the yarn density and yarn fineness are fixed. Thus, the binding depth of the conductive warp was gradually increased for the first four variants in order to increase the yarn undulation. Alternatively, the conductive weft system was doubled for the last variant with the aim of increasing the quantity of the conductive component. It should be noted that changing the weave structure requires less effort and energy while keeping the same threading of warps in the reed compared to altering the warp density. The EMSE was measured in an anechoic chamber and the shielding was satisfactory for all the variants in the frequency range of 1–6 GHz (19–44 dB). The results revealed that increasing only 7% of the waviness degree of the conductive warps led to 17% EMSE improvement due to increasing of the conductive yarns through the thickness of the variants. Moreover, no upward EMSE was detected for the last variant, despite the fact that the conductive weft system was doubled.

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New indicators on fabric drape evaluation based on three-dimensional model

Textile Research Journal ◽

10.1177/0040517519888669 ◽

2019 ◽

Vol 90 (11-12) ◽

pp. 1291-1300

Author(s):

Zhicai Yu ◽

Yueqi Zhong ◽

R. Hugh Gong ◽

Haoyang Xie

Keyword(s):

Point Cloud ◽

Three Dimensional ◽

Woven Fabrics ◽

Woven Fabric ◽

Angle Distribution ◽

Bending Rigidity ◽

Three Dimensional Model ◽

Fabric Drape ◽

Fabric Weight ◽

The Relationship

To evaluate the ability of woven fabrics to drape in a more accurate way, a three-dimensional point cloud of a draped woven fabric was captured via an in-house drape-scanner. A new indicator, total drape angle (TDA), was proposed based on the three-dimensional fabric drape to characterize the ability of a woven fabric to drape. The relationship between TDA and the drape coefficient (DC) was analyzed to validate the performance of TDA. The result indicated that TDA is more stable and representative than the traditional DC in characterizing the ability of a woven fabric to drape. In addition, the drape angle distribution function (DADF) of the triangular mesh was employed to describe fabric drape, as well as to bridge the gap between drape configuration and the warp bending rigidity of woven fabric. The results showed that the correlation coefficient between the real warp bending rigidity value and what was predicted warp based on DADF and fabric weight was 0.952.

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