Novel processing technology and mesoscopic geometric modeling of a new three-dimensional (3D) braided composite and the study on its longitudinal mechanical properties

Abstract

The paper investigates the processing technology and mechanical properties of a novel type of 3D-braided composite material, named as one-carry-two full five directional braided composite (1C2 3DF5d). The material differs from the conventional 3D-braided composites by doubling the number of braiding yarns in the cross section. This unique yarn architecture is achieved by the introduction of a novel yarn carrier path planning method and side (support) gear design on a rotary braiding machine. The proposed braiding machine and the preform manufacturing process are first compared to the established approaches in textile composite industry, namely the one-carry-one (1C1) method under a new classification scheme. A parametric representative unit cell (RUC) model of the new material is then established which reveals that the cross-section area is increased more than 58% compared to 1C1 braiding materials under the same braiding angle, and the fiber volume fraction is lower by 14%–16%. Damage propagation of the material under tensile and compressive loading conditions are simulated using finite element method based on the 3-d Hashin failure criterion. The longitudinal stiffness and strength of 1C2 3DF5d are compared to 1C1 3DF5d composites and demonstrate a reduction of more than 20% for both due to the lower fiber volume fractions. However, the loading carrying capability of the material is increased by 10%–20% due to the increased cross section area. The technology may serve as a new way to manufacture 3D-braided materials with large cross section and high load-carrying capabilities.