Simulating Prepreg Tack in AFP Process

Wrinkles, puckers and fiber bridging are among the major issues encountered in Automated Fiber Placement (AFP) process. These defects are all different manifestations of fiber misalignment. Residual stresses introduced in the tow during the deposition stage by the AFP head are the main driver for these defects. Tack between the deposited tape and the substrate is the resisting force against formation of such defects. Tack is a very complex phenomenon that is influenced by a variety of process parameters including temperature, head pressure and speed, as well as prepreg aging, moisture content and surface condition. A physics-based modelling framework for simulation of tack is developed in this study that allows for prediction of tack response. A model is also developed to simulate the deposition of the prepreg tape by the AFP head. It is shown that the model is capable of predicting AFP-induced puckers.