Abstract：A geometrical model was proposed for the 2D triaxial braided composites with the consideration of the undulation, the twist and the spatial interlacing of the yarns. Based on the volume-averaged method, an analytical model was developed for the prediction of engineering constants of 2D triaxial braided composites. Furthermore, a finite element model was established for the analysis of the mechanical properties by introducing an improved periodical boundary condition and the mesoscopic entity structure of 2D triaxial braided composites. The predication results of both models show good agreements with experimental results. The mesoscopic stress distribution of the material under loads was investigated and the influences of braiding parameters on the elastic constants were discussed. It shows that axial mechanical property is reinforced and the stresses are well-distributed; braid angle and fiber volume fraction have great influence on material’s elastic properties.
2013, Vol. 34 
