Characterizing friction for fiber reinforced composites manufacturing: Method development and effect of process parameters

In automated layup manufacturing processes of fiber-reinforced polymer composites, the quality of the manu-factured part is strongly dependent on frictional behavior. Improper control of frictional forces can lead to defect formation. Frictional sliding rheometry tests provide an innovative methodology to accurately characterize the tool-ply friction of unidirectional (UD) prepreg employing unique annular plate geometries. The effect of pro-cessing parameters (temperature, velocity, and normal force) on the frictional response of a carbon fiber prepreg was studied. Moreover, utilizing custom designed plate geometries coupled with optically transparent fixtures allowed for in-situ quantification of the prepreg-rigid surface contact area along with simultaneous character-ization of the process parameter-dependent frictional mechanisms. Our findings highlight the reduction in frictional forces with increasing temperature, attributed to the increased resin flowability, while increases in sliding rates resulted in a pronounced increase in the frictional forces. The effect of applied load on the frictional characteristics was more complicated due to contributions from both the adhesive and normal forces. Finally, the results were interpreted in light of the contact area measurements performed at different temperatures, normal force, and sliding rate.

Automated summary

In fiber-reinforced polymer composite manufacturing, frictional behavior plays a crucial role in determining the quality of the manufactured parts. By conducting frictional sliding rheometry tests, researchers were able to accurately characterize the tool-ply friction and investigate the effects of processing parameters on frictional response. The results showed that increasing temperature reduced frictional forces due to increased resin flowability, while increasing sliding rates significantly increased frictional forces. The influence of applied load on frictional characteristics was more complex, involving contributions from adhesive and normal forces. Contact area measurements at different temperatures, normal forces, and sliding rates provided insights for interpreting the results.