Forming of Thermoplastic Composites

Abstract

Design and production guidelines for UD reinforced thermoplastic composites are highly desirable. Therefore, forming experiments and simulations with a realistic complex shaped product were conducted. Thermoforming experiments with quasi-isotropic UD carbon/PEEK and 8HS woven glass/PPS composites showed a clear difference in formability. Many wrinkles develop near doubly curved areas for the considered UD composites, whereas significant in-plane shear is observed for the woven composites. Forming prediction tools can be utilised to optimise the product design with respect to formability. A forming prediction methodology is shown, which encompasses finite element modelling in combination with material models that describe major deformation mechanisms. Characterisation methods were developed to describe inter-ply friction and in-plane shear. Forming simulations are able to indicate the critical areas for the UD composites, as is concluded from the comparison of wrinkling and in-plane shear distributions within the formed specimens. Forming experiments and predictions match qualitatively well and this tool can successfully be utilised in the product design phases.