NUMERICAL PREDICTION OF THE LONGITUDINAL AND TRANSVERSAL MODULI OF THREE DIMENSIONAL AND 4-STEP BRAIDED COMPOSITES

Shear properties of the composite is studied by using the parameterized modeling technology for three dimensionally and 4 step braided composites and based on the “米” type model of a representative unit cell presented for FEM numerical prediction. First, the boundary conditions of the unit cell are discussed under shear deformation. Then, the shear moduli of the composite are predicted by FEM calculation. Finally, the relations of the shear moduli varying with different braiding angles and fiber volume fractions are concluded by analysis for the results.