Abstract: Composites are increasingly used in aerospace and automotive because of their high strength and stiffness. Among the production technologies, Automated Fiber Placement (AFP) is a high-efficiency one to manufacture high-quality composites, especially for complicated surface structures. During the process of AFP, path planning is an essential technology and the coverage of fiber path has a great impact on the strength of composite parts. When the fiber is laid on the mould, the distance between adjacent laying paths can′t be kept constant due to the complex shape of structures, and it will cause many fiber overlaps and gaps. Although overlaps and gaps can be reduced by applying the tow cutting and restarting operation, the existing methods just select a fixed operation position. This strategy doesn′t take into account the geometric features of structures. To overcome this problem, the paper proposed a novel strategy in which the position of the tow cutting and restarting is dynamically adjusted. Firstly, the fiber overlap and gap in various situations are analyzed. Then, an optimization model is established, in which the total area of the fiber overlaps and gaps is defined as the optimization objective. By optimizing the position of the tow cutting and restarting, the area of fiber overlaps and gaps can be reduced effectively. Finally, a series of simulation experiments are conducted, the optimization leads to a 66.67% and 20.41% reduction in the total area of fiber overlaps and gaps, respectively, in the two situations at most, which is a considerable improvement compared to the existing method. Therefore, the fiber cutting and restarting strategy proposed in this paper can indeed reduce the fiber overlaps and gaps, it can improve the quality of composite parts.

Key words: composites, automated fiber placement, fiber path coverage, tow cutting and restarting