| The geometrical parameters and the fiber volume fractures (FVF) of the 3-D woven fabrics are necessary to calculate the elastic properties as well as other mechanical properties of the 3-D woven composites by using the meso-mechanical method. This paper Mainly focused on the meso-architectures of 3-D orthogonal woven fabrics. The geometrical parameters and FVFs are calculated by using unit cell model, and improved by macro-unit cell model. By analyzing the FVF's influential factors, it is found that along with the increasing ratio of warp yarn count with weft yarn count (Texy/Texx), the FVF in warp direction, as well as the fabric total FVF, will increase, but FVF in weft direction will decrease. This result means that warp tows have more important influence on the fabric FVF than weft yarns. It is also found that along with the increasing space ratio of warp yarns with weft yarns (Dx/Dy), FVF in warp direction and fabric total FVF all decrease, but FVF in pick direction will increase. Binder yarn FVF depends only on its thickness and the densities of warp yarn and weft yarn. The thicker the binder yarns, the smaller the warp, weft and fabric total FVFs, with exception in binder yarn's FVF. As a result, the binder yarn should be a little thinner in the designing of 3-D orthogonal woven fabric.Two very important parameters (take-up length and dent count) in loom set-up are connected with FVF, and this is the foundation for manufacturing woven fabric with required FVFs in composite design.Fabric geometrical parameters based on unit cell model and fabric's FVFs based on macro-unit cell model are perfectly fitted to the orthogonal woven fabric with square shape binder path, but there are some differences for the fabric with sine-line binder path which is the more practical shape.Based on the binder yarn shapes in the nine 3-D orthogonal woven composites using different binding methods, a binder yarn path model was introduced with the combination of sine curve and straight line. In a macro-unit cell, equations are set up with fabric geometrical parameters as unknown variables. As the equations are nonlinear, a program was provided using Matlab software and Newton's method.Calculation was carried out by using the computer and geometrical parameter resultswere achieved.The modeling binder path is compared with the practical testing one and coincideswith the latter. For convenience of the comparison and application, method forcalculating the binder path length is set up in accordance with Newton-Cotes methodunder the aid of computer. The binder shrinkages, which are more useful in fabricproduction, are converted from binder path length, and compared with the testingshrinkage results. There is no distinct difference between the two shrinkages and thisis the proper demonstration for the binder path model.The FVF's calculating method is revised using macro-unit model and the newlycomputed results are compared with the practical ones. Their identical propertiesproved that the computed results could be used to represent the practical ones.In order to prevent inclining weft columns, the selected take-up mechanism has theability to change pick density in the weaving process of 3-D orthogonal fabrics. It alsoleads the fabric in plane motion so as to ensure identical warp yarn length that isimpossible if using traditional roller taking-up.Multi-beam can satisfy the different warp yarn consumption requirement. In warppreparation, yams rolled in one beam have the same yarn consumption in weavingprocess, and different beam can have different yarn consumption. Drop weight tensiondevice can assure the constant warp tension no matter in warp shedding or in close-up.Drop weight position should be controlled to minimize the influence of warp yarntension.Smaller binder warp tension is fitted for denser and thicker fabric, but may affect theclearness of the shed.In the weaving of binder weft orthogonal fabric, there exists a process for binder yarn...
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