Abstract: In this paper, Z-shaped frame parts with curvature and complex structure were prepared by the automatic roll forming technology of composite materials. However, during the roll forming process, the prepreg is subjected to complex thermal/mechanical effects, resulting in defects such as in-plane buckling or out of plane wrinkles in the frame. In this paper, different process parameters and structure parameters were analyzed theoretically and studied experimentally. The effects of temperature, speed and lay-up structure on the formation of defects were discussed through defect observation and characterization. The temperature affects the state of the resin in the prepreg, which affects the change of the slip mechanism and leads to the defects. The velocity determines the sufficiency of structural response of prepreg. The change of layering changes the interlayer shear, interlayer slip and friction, and then affects the generation of defects such as wrinkles. The results show that the best roller preforming effect is achieved at the temperature of 50 ℃ and the speed of 50 mm/min. The research results in this paper can provide theoretical guidance for parameter optimization of roller preforming process.

Key words: Z-shaped frame, roll forming, preforming, wrinkles, process parameters, structural parameter, composites