Abstract: Three-dimensional stitching technology can not only significantly improve the inter-laminar properties of composite materials, the delamination resistance and impact damage tolerance, but also combine the liquid forming process to realize the integrated structure of composite materials. In this paper, the single-sided stitching technology of composite materials was taken as the research background, and the study on stitching equipment for single-sided curved needle of composite materials was carried out. By analyzing the functional requirements of the stitching equipment, the overall planning scheme of the equipment was proposed, and a single-sided curved needle stitching head was designed and developed. Subsequently, the stabilizing forming factors of the stitches were discussed and analyzed. The displacement-time relationship between the end effector of the stitching head in a stitching cycle was determined, and the optimal loop shape and the expression of the balance of supply and demand of the thread was derrmined. Finally, the trial sewing test proved that the stitching equipment can form a smooth and stable chain stitch on the fiber preform, and achieve good stitching effect.

Key words: composites preform, single-sided curved needle stitching, blind stitch, equipment design, steady-state loop