Modelling slit tape buckling during automated prepreg manufacturing: A local approach

This paper investigates the local buckling of slit tape in the Automated Fibre Placement process for a circular fibre path using an analytical approach that accounts for prepreg tack and stress distribution. Curing effects are not considered in this study. The main objective is to define the critical buckling load and therefore the minimal steering radius for which no tow wrinkling occurs. Simulations are performed for the buckling of the first ply, using a tack parameter governing the interaction between tool and material. A sensitivity analysis of the most relevant parameters of the model is performed. Numerical results show that lower values of the steering radius are obtained for lower tow width values and higher prepreg tack values. Experimental investigations show that the estimation of wrinkling occurrence in steered fibres could be improved by taking into account certain additional parameters, such as lay-down rate, temperature and the dynamic behaviour of the resin.