• Pierik, Rens
• Grouve, Wouter J. B.
• Wijskamp, S.
• Pierik, E. R.
• Akkerman, Remko
• Grouve, W. J. B.

Abstract

<p>Excessive ply–ply friction can lead to process-induced defects during the hot press forming of thermoplastic composite laminates. Process simulations can be used to enable first-time-right defect-free manufacturing. However, a good understanding of the ply–ply friction is required to improve the constitutive models to allow simulation of more complex parts. We performed friction experiments on UD C/PAEK tapes, showing a typical response with a peak followed by a steady-state friction. Micrographs of tested specimens were analyzed to evaluate the matrix interlayer thickness distribution in the ply–ply interface, which we combined with the matrix viscosity to predict the peak friction. Generated fiber distributions, mimicking the ply–ply interface, were successfully used to obtain the matrix interlayer as well. The steady-state friction was accurately described by including a critical shear stress to represent wall slip, substantiating the concept of wall slip as the dominant underlying mechanism for the start-up friction response.</p>

Topics

• impedance spectroscopy
• experiment
• simulation
• composite
• viscosity
• defect
• forming
• thermoplastic