The prediction on mechanical properties of 4-step braided composites via two-scale method

The two-scale method (TSM) is successfully applied to the prediction for the mechanics parameters of 4-step three dimensional braided composites, including stiffness parameters and strength parameters. The two independent micro-structure parameters, the braiding angle and the fiber volume fraction, are investigated in this paper. Both of them are implicitly included in the fabric of the unit cell of 4-step braided composites with 1 × 1 pattern. They directly influence the strength of 4-step braided composites, including tensile strength, bending strength and torsion strength. And then, the curves of the strength along with the braiding angle and the fiber volume fraction are illustrated. By the comparisons with experimental data, the two-scale method is validated to predict the mechanics parameters of 4-step braided composite materials.