Abstract:
Recycled carbon fibers (RCF) are mostly fluffy and disorganized short fiber bundles, which can be reoriented based on wet fiber orientation technology. Conventional fiber-reinforced composites are usually layered with fibers in a unidirectional direction, which makes it difficult to fully utilize the gain effect of the fibers on open-hole parts, but the structural properties of the composites can be improved by curved layups of the fibers. The optimal configuration parameters of certain RCF content with different concentrations of hydroxyethyl cellulose (HEC) were investigated by designing fiber dispersion experiments. Using the self-constructed fiber orientation path control device, the prepared dispersion was spread to obtain fiber mats with different trajectories and shapes, and the orientation effect of RCF was evaluated based on a two-dimensional fast Fourier transform (2D FFT). The open-hole specimens of RCF/epoxy resin (EP) composites were prepared by molding, and the effects of different layup paths on the load-bearing capacity of the open-hole specimens were analyzed. The results show that the optimal HEC concentration is 14 g/L when the 6 mm RCF content is 6 g/L. The open-hole specimens prepared according to the curved path effectively reduce the stress concentration at the open hole, and the ultimate load is increased by 69.5% and 35.9% compared with the open-hole specimens prepared according to the unordered path and the horizontal path, respectively. The study broadens the design freedom of RCF/EP composite structures and provides a reference for realizing high-performance reuse of RCF.