Abstract: Automated fiber placement as an advanced composite automated molding technique is widely used in aerospace and other fields, where the use of variable angle automated fiber placement can improve the design space of aerospace structures, which is of great significance to improve the overall mechanical properties of the components. However, the current processing technology of the variable angle automatic fiber placement technology is not mature, and manufacturing defects are inevitable in the forming process, which has adverse effects on the mechanical properties of the components. The characteristics of manufacturing defects and their main influencing factors in the process of variable angle automated fiber placement are summarized. The working principle of automated fiber placement and the advantages of variable angle placement are introduced. The formation mechanism and the effects of the gap, overlap, and wrinkle defects on the mechanical properties of variable stiffness laminates are analyzed. The types of factors influencing the manufacturing defects of variable angle placement and mechanism are discussed in depth. Furthermore, the suppression methods of manufacturing defects are discussed. Finally, the shortcomings of the variable angle automated fiber placement in current research are summarized and the future research trends of the technology have been prospected.

Key words: automated fiber placement, variable angle laying, manufacturing defects, process parameters, suppression methods