A Review of Fiber Yarn Friction in the Forming Process of Textile Composite Preforms

Preforms are the reinforcements of textile composites, which directly affect the mechanical properties of composite materials. Three-dimensional(3D) preforms are often made into composites with excellent mechanical properties and low mass. Compared with 2D preforms, the delamination resistance and impact damage tolerance of the composites can be significantly improved. 3D preforms can be used to quickly produce near-net complex-shaped components, e.g. radome, rocket throat and multi-tube bracket, using varieties of high-performance fiber materials (e.g. carbon, aramid, UHMPEF). However, fiber is the basic unit of the preform. Friction and wear of fiber/tows is a common problem during 3D performs forming process. The research shows that the loss rate in the mechanical properties of the preforms is as high as 5%~30% due to friction, compression and bending. Among them, the loss rate caused by friction is as high as 9%~12%. For example, during the beating-up stage of the 3D orthogonal weaving process, tows are subjected to friction and wear, resulting in a large amount of hairiness in the preforms, which leads to result in the decline of mechanical properties and design limitations of the composite. At present, in order to meet design requirements, production departments are forced to use high-cost fibers to compensate for defects. Therefore, it is of significance to research the friction and wear behavior of fiber/tows in the forming process of complex 3D preforms, which will contribute to improving the mechanical properties and service life of the composites and reduce the maintenance cost. Since the 1980s, researchers from Britain, France and the United States have engaged in the friction and wear behavior of tows by reciprocating friction method, pull-out method and capstan friction method. However, the friction research of fiber\tows started late in China, and some research institutions mainly focus on improving its wear resistance during fiber production. The research about contact deformation, friction and wear mechanism of tows with complex structure preforms is still lack of in-depth work. Therefore, it is important to reveal the friction and wear mechanism of tows in the weaving process and improve the comprehensive property of preforms. In this review, the recent researches on the friction behavior of tows-metal and tows–tows are reviewed. Firstly, the advantages and disadvantages of tows-metal and tows-tows friction testing methods are summarized. Secondly, the influence mechanism of angle, frequency, pretension and normal load on the friction performance of tows is analyzed. Finally, the theoretical analysis model of tows of friction and wear is summarized. This review has a certain guiding significance for forming process and quantitative analysis of friction and wear of textile composite preforms.