Roll forming continuous fibre-reinforced thermoplastic sheets: experimental analysis

This paper describes the results of an experimental roll forming study performed on sheets of continuous fibre-reinforced thermoplastic (CFRT) material. The deformation length, or transitional region over which the material deforms under each roll station, is studied for various temperatures, laminate configurations, and roll settings using still photography and surface grid strain techniques. The severity of the deformation through the first forming pass has been found to be related to the fibre architecture as well as the forming temperature. The kinematic constraints imposed by the fibres are found to result in a trellising effect that is observed clearly using surface grid strain techniques. Finally, as a first step in the theoretical analysis of the process, kinematic relations are developed, which describe the rate of change of strain in a sheet through the deformation zone.