Two-dimensional models are presented for the elastic analysis of a plain weave fabric lamina. These models take into account the actual fabric structure by consid ering the fiber undulation and continuity along both the warp and weft directions, possible presence of gap between adjacent yarns, actual cross-sectional geometry of the yarn and possible unbalanced nature of the plain weave fabric. Typical studies on the effect of fiber undulation and lamina thickness on the in-plane elastic constants are presented. A large discrepancy, similar to that reported in literature, is found between the predicted elastic moduli of plain weave fabric lamina by ID WF models and experimental results. On the other hand, the predictions of 2D WF models are fairly good since the two-dimensional extent of the fabric is considered in these models.

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Two-dimensional models are presented for the elastic analysis of the plain weave fabric laminates. A methodology to generate the laminate configuration from the lamina configuration is given. The effect of lamina configuration and their relative positions with respect to each other on the in-plane elastic constants of the woven fabric laminates is studied. A laminate configuration with optimum shifts gives higher elastic properties compared to the other configurations. A comparison between in-plane elastic moduli of the unidirectionally laminated symmetric cross-ply laminates and plain weave fabric laminates is made. The in-plane elastic moduli of plain weave fabric laminates predicted by the models are found to be in good agreement with the experimental results.

Two-dimensional woven fabric composite models were developed for the elastic analysis of WF composites in Part I of this paper. The effect of undulation of yarn and fabric thickness on the elastic properties of woven fabric lamina was studied. The study was extended to woven fabric laminates and the effect of laminate configuration on the elastic properties was analyzed in Part II. In the present paper, the effect of gap be tween two adjacent yams on the elastic properties of woven fabric lamina and the effect of laminate configuration for different number of layers on the elastic properties of woven fabric laminates for different material systems are studied. An optimum gap between adja cent yarns gives higher Young's moduli, and it depends upon the fabric structure and material system. A basic building block is found which gives higher elastic properties than with any other configuration with the same number of layers. Such a basic building block can then be used for making thicker laminates. The comparison of woven fabric laminates with UD cross-ply laminates indicated that, in general, the material system with lower de gree of orthotropy is desirable for woven fabric composites.

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