The Simulation Design Of The Three-Dimensional Tubular Woven Composite And Its Numericalanalysis Of The Mechanical Properties

The fiber reinforced polymer composites are now widely used to take the place of metal because of the high specific strength and specific stiffness. Three dimensional woven composites is a kind of spatial net-shape fabric structure, which formed by interlacing binding threads in the thickness direction to join layers of warp and weft together, cured with matrix under certain condition. The composites have good structure designable ability, excellent mechanism performance, low cost and strong capacity in simulating shapes.3D woven composites have drawn more and more attention along with broadly applied in aeronautics, astronautics, bio-medical engineering and automobile industry, etc. The tubular structure is a form which utilized in engineering frequently. Binder yarns are woven into the tubular structure of composites while producing by3D textile processes and the material not only perform well for in-plane mechanical properties, but also get a great improvement for through-thickness properties compared with2D laminated ones. In order to design and use3D woven tubular composites more effectively, an intensive investigation should be made to its microstructure and mechanical properties.The numerical analysis of three-dimensional woven composites mainly uses the method of micromechanics. We can make the woven composite micromechanical model, then predict its mechanical properties by the finite element method. The chief content can be fallen into three parts as below:In the first part, by assuming the fiber cross-section as long circle shape, the3D circular weave composite is studied. A novel geometric model, cuboid unit cell, was established to represent the fan-shaped unit cell of tubular fabric with the same volume, and the fiber volume fraction was calculated. The geometric structure of3D circular weave fabric is expressed by a group of numeric parameters and the mechanical model is established to predict engineering elastic constants of the fabric. The second part aims to finite element analysis of carbon fiber woven tubular composites and carbon fiber bicycle. It has instructive significance for design and manufacturing in the future.