A review of defect formation, detection, and effect on mechanical properties of three-dimensional braided composites

Abstract

Three-dimensional (3D) braided composites have received much attention in the fields of aerospace, the automotive industry, etc., due to their unique structure and excellent performance. However, due to the complexity of their preparation process, the generation of defects is almost inevitable. With its wide application, it has become crucial to understand and control its defects. This article reviews the research progress on the defects of braided composites. First, it analyses the connection between the molding process parameters and the formation of void defects. It also introduces some nondestructive testing methods and principles for defects in 3D braided composites. Second, for the yarn deformation defects caused by the extrusion of component materials, the relevant assumptions about cross-sectional deformation and uniform yarn orientation are summarized, and the law of the influence of yarn distortion randomness on the material properties is summarized. For void defects, the differences and connections between the matrix porosity model and the matrix/yarn porosity model are discussed. In addition, the effects of other types of defects on the material are summarized. Finally, based on the summary of existing results, the prospect of future research directions is proposed.

Keywords

• 3d braided composites
• defect
• mechanical properties