A Numerical Model Of Woven Fabric Composites

Woven fabrics composite are widely used in the aerospace, automobile and marine industries. High-performance components can be composed of a stack of unidirectional laminates or 2D woven fabric plies arranged in a sequence chosen to optimize the mechanical properties. Woven fabric presents various attractive aspects,such as low fabrication costs, ease of handling, high adaptability, and, in comparison with tape laminates, better out of plane stiffness, strength and toughness.A procedure is presented for the numerical evaluation of the mechanical properties of woven fabric composite material. Woven fabrics usually present orthogonal interlaced yarns and distribution of the fibers in the yarns and of the yarns in the composite may be considered regular. This allows us to apply the homogenization theory for periodic media both the stiffness and the strength of woven fabric composite material. In the mechanics of composites material the term homogenization indicates the passage from the micro to the macro scale to relate the mechanical properties of the composites material to the properties of the single phases. The geometrical variables of the fiber and resin types may be varied to reach the required mechanical properties. The model includes all the important parameters that influence the mechanical behavior: the lamina thickness, the yarn orientation, the fiber volume fraction and the mechanical characteristics of the components. The capabilities of the numerical model were verified studying the elastic behavior of a woven fabric laminate available in the literature and the ultimate strength of a glass fabric laminate experimentally investigated.The procedure, which can be implemented into commercial finite element codes, appears to be an efficient tool for the design of textile composites.A kind of homogenized numerical model of woven fabric composite material is presented, which provides a simpler and more accurate numerical method for engineering applications. At first, a cell model with fine FE mesh is established for the representative cell of the woven fabric composite material, which can provide more actual simulation of the cell's structure than other micro-mechanical models by relaxing the assumption and making the premise simpler. And then the results of the FE analysis of the cell model are introduced into the three dimensional penalty equilibrating element based on the Hu-Washizu variational principle. In this way, a kind of woven fabric composite material with meso-structure can be formulated as the equivalent homogenized element, which can be applied in macro-structural analysis. This kind of element is applicable for the homogenization of the thin cell's structure, which solves the problem that normal solid elements may cause big error and shell elements can only deal with structures with one layer. A general FE model was established for the cell and Fortran programs were designed for the macro-mechanical computation. Numerical examples are given to compare the results obtained by the presented approach with experimental and other numerical results, and to show the efficiency and applicability of the presented numerical method.