A thermo-viscoelastic approach for the characterization and modeling of the bending behavior of thermoplastic composites – Part II

A proper description of the bending behavior is crucial to obtain accurate forming simulations, especially for continuous fiber-reinforced thermoplastic composites. These materials exhibit a highly temperature and bending-curvature dependent bending stiffness. These dependencies make the property challenging to characterize with conventional characterization methods, and therefore require novel techniques. The first part of the study has shown how Dynamic Mechanical Analysis and a rheometer-based method can be used to examine viscoelastic bending behavior. This subsequent part focuses on combining their advantages in a universal characterization method, which provides an accurate description of the bending behavior over a broad temperature range, including the phase transition of recrystallization. Dynamic isothermal experiments as well as dynamic experiments over defined temperature ranges were conducted. The aforementioned experiments were reconstructed in simulations, employing the non-linear viscoelastic material model from the first part of the study, to evaluate the characterization method and to further validate the model.