Abstract: Based on the bead-chain model, the discrete element method is used to flexibly treat the fiber model. And the EDEM-Fluent coupling simulation model is built to simulate the flow orientation process of flexible recycled carbon fibers in the convergent flow field. Fibers with a length of 6 mm are reoriented and arranged by wet orientation technology to prepare oriented fiber felt, and the simulation results are compared with the experimental. Carbon fiber/epoxy resin fabricate specimens are prepared by compression moulding and their mechanical properties are characterized. Results show that in the process of the fibers following the fluid movement, the fiber is affected by axial shear force, resulting in varying degrees of bending deforming, and the direction also rotates along the direction of the fluid flow, and the orientation is completed during the movement. The preferential alignment degree of fiber felt is characterized by two-dimensional orientation tensor, which is 98%. The bending strength and modulus of the prepared oriented composites are increased by 70.6% and 88.5% compared to the unoriented composites.

Key words: fiber orientation, flexible fiber, discrete element method, convergent flow field, mechanical properties