Unit cell eigen-element of 3-D orthogonal woven composites and its applications

As for 3-D orthogonal woven composite, a new homogenized eigen-element method is proposed in this paper. The term 'eigen-element' means that the element can depict the characteristics of geometry and material configurations. The global stiffness matrix of 3-D orthogonal woven composite unit cell is obtained u-sing the ordinary finite element method with the eigenvectors of the global stiffness matrix and the eigen-element of the unit cell is constructed. After comparing the stiffness matrix elements of the eigen-element with those obtained by conventional homogenization method, it's shown that the eigen-element can depict the details of geometric and material configuration of the unit cell. In order to validate the eigen-element, the inherent frequencies of 3-D woven composite beam are computed by eigen-element method, conventional homogenization method and ordinary finite element method respectively, the results demonstrate that the eigen-element is more precise than the conventional homogenization method, and the amount of computational work reduce greatly comparing with the ordinary finite element method.