关键词: 碳纤维, 展丝织物, 抗弯性能, 抗冲击性能, 展宽

Abstract: Carbon fiber composites are regarded as key strategic materials due to their excellent properties such as light weight, high strength, fatigue resistance, and corrosion resistance, showing broad application prospects in civil fields. To promote their use in civilian applications, it is essential to adopt large-tow carbon fiber composites that are simple to manufacture and low in cost. With advances in fiber spreading technology, spread-row fabrics made from large-tow carbon fibers have been widely used in railway vehicles, military, aerospace, and other fields. In traditional woven fabrics, yarn crimping occurs during the interlacing of warp and weft threads, leading to stress concentration and significantly compromising fabric performance. Currently, researchers have explored the use of carbon fiber composites prepared by spreading large-tow carbon fibers as raw materials to produce spread-tow fabrics, demonstrating their feasibility in aerospace and rail transportation applications. However, most of these studies have focused on the tensile and compressive properties of materials, while relatively few studies have been conducted on the bending resistance and impact resistance of composite fabrics. This study employs three types of 12K carbon fiber plain weave fabrics with different spreading widths as experimental subjects. A detailed layup and resin injection plan was developed, and composites were fabricated using VARTM technology. Three-point bending and low-velocity impact tests were conducted to evaluate the mechanical performance of these composites. The damage mechanisms and reasons for differences in mechanical properties were analyzed, providing fundamental data and technical reference for applied research on spread-row fabrics. The results indicate that, compared with traditional fabrics, the spread-row fabrics exhibit significantly improved flexural load capacity and impact resistance, along with altered deformation behavior. In terms of bending performance, the flexural strength increases by up to 17.49% and 52.11%, respectively, for the two types of spread-row fabrics. Regarding impact resistance, the peak impact load increases by 35.16% and 40.13%, respectively, with increasing yarn width. Furthermore, traditional fabric composites show much greater maximum displacement than spread-row fabric composites, while the energy absorption capacity of the latter improved with larger yarn width. In conclusion, spread-row fabric composites outperform traditional woven composites in both flexural and low-velocity impact properties, and their performance further improves with increased yarn width.

Key words: carbon fiber, spread-tow fabric, flexural performance, impact resistance, spreading widths