From mixed to hydrodynamic regime in lubricated sliding of carbon fiber tows

Abstract

Carbon fiber tows are used as reinforcement material in composite elements. To ensure mechanical integrity of the composite structure, it is important to ensure a good positioning of the carbon fibers in the mold during the manufacturing process. The positioning of the carbon fiber tows depends greatly on the friction with the mold. In the present paper, the friction between a carbon tow placed on a cylindrical pin rubbing against a rotating glass disk is experimentally studied in both dry and resin-lubricated conditions on a dedicated tribometer. The tests are performed for different loading levels and sliding speeds. The results are compared to numerical simulations taking into account contact mechanics and lubrication. The tows are modeled using a simple elastic foundation approach coupled with the Reynolds equation when the resin flow is considered. It appears that the impact of the deformability of the tow on its frictional behavior is significant. It conditions the transition between mixed and hydrodynamic lubrication regimes.