2D weave

The design of 3D weaves is more complicated than for 2D weaves, but a program. Weave Engineer, based on mathematical principles by Chen et al. (1996), is available from TexEng Software Ltd. It is easy to use in a series of steps. A typical output, which can be used as input to the control software of a weaving machine, is shown in Figure 12. 

Before we deal here with two distinct woven fabric categories, commonly called 2D weaves and 3D weaves, it is worthwhile to establish first the basic terminology. 

D multilayer woven fabrics made on conventional 2D weaving looms are commonly distinguished as warp interlock and weft interlock these two subcategories have certain similarities but also possess substantial differences. Warp interlock 3D woven fabrics were introduced much earlier than the weft interlock ones (see inventions in... 

Although traditional 2D weaving looms may adapt well to making multilayer panels of somewhat limited thickness, the whole fabric thickness is built up layer-by-layer, one pick at a time, which reduces the productivity of this manufacturing process even at high weaving speeds. Note that the production speeds are limited by other factors, as explained later. 

Besides flat solid fabric panels of uniform thickness, some more complex shapes have been produced and reported in the literature. For example, T-sections, 1- and L- profiles, variable thickness solid panels, and integral core stmctures with orthogonal or inclined webs (simulating box beams and tmss-like stmctures) have been demonstrated. Still, by the nature of traditional 2D weaving, where the warp and weft yam sets are mutually orthogonal in the fabric plane, the described multilayer weaving technology does not allow to introduce in-plane bias yams. 

This t q)e of fabric preforms can be produced either on the specialty weaving machines or (in limited thicknesses) on conventional 2D weaving looms both these machine types are fully automated and have been already used for industrial-scale fabric production. 

Khokar, N., 1996. 3D fabric-forming processes distinguishing between 2D-weaving, 3D-weaving and an unspecified non-interlacing process. J. Text. Inst. 87 (1), 97-106. 

The weave for each fabric layer is recorded in a 2D matrix. The 2D weave matrix representing the overall weave for each area will be able to be generated by combining the 2D matrices of all fabric sections in the area concerned. Suppose there are n fabric layers in the area of concern. The weave for layer i is recorded in matrix M, ( = 1, 2,. .., n), and the element of this matrix at the xth warp and the yth weft is Mj x,y) (1 < X < r,g, 1 < y < rjp) where r,g is the number of warp ends in M, and the number of weft picks in M,. /, is the length of layer i. 

D weaving The weft yarns are inserted over and under the multiple layers of warp yams. This process yields thicker woven structures than in 2D weaving where only one single layer of warp is used. 3D woven preforms have higher strength in the thickness direction than the 2D woven fabrics however, their strength decreases in the in-plane directions due to the fiber crimp. 

D weaving is a high-speed, economical process that been used for thousands of years. Fabric is formed by warp and weft yams that are interlaced with each other in the 2D-weaving process. 

Figure 4.18 Stages in 2D weaving (a) shedding, (b) filling and (c) beat-up.

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