Abstract: In this paper, a finite element model was established based on meso-mechanics to predict the tensile modulus of braided RVE. Firstly, a two-dimensional triaxial braided structure model was established by parametric modeling, and the effect of braided angle on the thickness and fiber content of braided circular tube was studied by comparing with the actual sample. The results show that with the same modeling method, as the braiding angle increases, the fiber volume content increases first to a certain level and then remains steady at the level. When the monolayer thickness becomes thinner, and the fiber extrusion and accumulation is reduced. Then, the stress, strain and modulus of representative volume element were predicted by finite element simulation. The predicted results are in good agreement with the experimental results. Finally, TORAY T700 carbon fiber and epoxy resin were used to braided 2D triaxial tube. According to GB/5349 standard, the axial tensile test of 2D triaxial braided tube was carried out in order to study the effects of different braided angles on the axial tensile properties of 2D triaxial braided tube and those of braided angles on the modulus. The results suggest that the smaller the braiding angle, the higher the modulus and the better the axial tensile property.

Key words: braided round tube, tensile test, braiding angle, tensile modulus