Abstract：As for three-dimensional braided composites manufactured by the resin transfer molding (RTM) process, it is difficult to avoid the formation of void defects in the composites. Firstly, the generation mechanism of the void defects in the process of RTM was analyzed. The void defects mainly include the dry patches in the fiber-bundle and the voids in the resin matrix pocket. Then, a simple model for describing the random void defects distribution was presented. Based on the unit cell model containing the random void defects, a new finite element model was put forward to predict the effective elastic properties. Considering the random distribution of void defects, the probability statistics analysis was done by establishing the samples. Finally, the effect of the void volume fraction on the elastic properties was discussed in detail. The presented model can be utilized to predict the mechanical properties of 3D braided composites with random void defects.
Keywords: braided composites; elastic properties; void volume fraction; random defects; probability statistics
2013, Vol. 34 
