不同针刺工艺的针刺复合材料面内拉伸强度分析

The in-plane tensile strength of six carbon fiber reinforced resin-based composites with different needle punching processes decreases with the increase of needle punching density and needle punching depth. The fiber fracture at the needle punching regions can make the defects instability propagation in the material, which can induce the tensile failure of material. Based on the in-plane tensile test results and fiber cumulative damage theory, a theoretical model for analyzing in-plane tensile strength of needle punched composites are established by introducing fiber volume reduction coefficient. The prediction results of this model are consistent with the experimental results. It is found that the number of broken fiber clusters is related to the volume reduction coefficient. The model can be used to predict the in-plane tensile strength of composites with different needling processes, and to guide the design of the needle punching preforms.