Abstract: In light of the increasing utilization of composite materials in civil aircraft and the pressing demand for domestic production, enhancing the manufacturing efficiency and forming quality of composite structural components has become a pressing issue. To avoid defects such as wrinkles, buckling, and uneven thickness during the preforming process, it is imperative to comprehensively characterize the formability of prepregs. This characterization serves to evaluate the manufacturability of the materials, providing references for material selection and performance improvement, and furnishing data for the establishment of finite element simulation models. In comparison to woven prepregs, unidirectional prepregs find broader applications in civil aircraft composite structural components, especially for the manufacturing of main load-bearing structural components with high strength requirements. Therefore, characterizing the formability performance of unidirectional prepregs becomes crucial. This paper systematically reviews domestic and international research achievements in the forming performance testing of unidirectional prepregs, specifically focusing on compression, intra-ply shear, interlaminar slip, and bending properties. Additionally, the paper explores the future directions in the development of preforming performance tests for prepreg.

Key words: unidirectional prepreg, forming, compression, intra-ply shear, interlaminar slip, bending, deformation mechnism