Micro-CT based parametric modeling and damage analysis of three-dimensional rotary-five-directional braided composites under tensile load

Three-dimensional (3D) braided composites have broad applications in aviation and aerospace fields due to their outstanding mechanical properties. However, the damage mechanism of 3D braided composites fabricated by rotary braided composites is still unclear. In this paper, a parametric finite element modeling of 3D rotary-fivedirectional (3DR5d) braided composites is established, considering the realistic yarn cross-section based on a Micro-CT scan. A systematical approach for damage prediction is developed to analyze the damage behaviors of 3DR5d braided composites. The tensile mechanical properties and damage evolution of 3DR5d braided composites are predicted based on the proposed method. The accuracy of the proposed model is verified by the comparison with the data in the literature. The effect of braiding angles and fiber volume fractions on the mechanical properties and damage mechanisms of 3DR5d braided composites is investigated based on parametric analysis. The results show that the strength and modulus of 3DR5d braided composites increase with the decreasing braiding angle and the increasing fiber volume fractions. Moreover, transverse shear gradually dominates in the failure of 3DR5d braided composites in the tension process. The results could be beneficial to guide the design and fabrication of 3DR5d braided composites.

Automated summary

In this study, a parametric finite element model of 3D rotary-fivedirectional (3DR5d) braided composites was developed, taking into account the realistic yarn cross-section based on a Micro-CT scan. The proposed method was used to predict the tensile mechanical properties and damage evolution of 3DR5d braided composites. The effect of braiding angles and fiber volume fractions on the mechanical properties and damage mechanisms of 3DR5d braided composites was investigated.