An analytical friction model for fibre tow slippage in Tailored Fibre Placement preforms based on pull-out experiments

Abstract

Fibre tow slippage in conventional reinforcement forming is a major defect which can be turned into an additional degree of freedom in preforms made by Tailored Fibre Placement (TFP). Controlling slippage of reinforcing fibre tows, which are deposited on a conventional reinforcement using the TFP technology, is an advantage which enlarges the preform design space Fial et al. (2018). Moreover, when TFP is used to locally reinforce a conventional reinforcement, slippage of the deposited fibre tow during forming, is required depending on its orientation relative to the conventional reinforcement layout to avoid defects. Therefore, characterizing the friction behaviour of the reinforcing fibre tows is necessary to take advantage of its slippage as an additional degree of freedom. In this paper, an analytical friction model describing the interactions of the fibre tows with the backing material and the stitching yarn in TFP preforms is developed based on pull-out experiments. A parametric study allows expressing the parameters of the analytical friction model as function of the stitching parameters.