Predicting the low-velocity impact behavior of polycarbonate: Influence of thermal history during injection molding

• Yield stress of PC is evaluated by the temperature history during injection molding.
• The influence of processing thermal history on impact behavior of PC is studied.
• Fracture energy of PC in Izod test is increased as the mold temperature increases.

The influence of the thermal history experienced during injection molding on the low-velocity impact behavior of polycarbonate (PC) is investigated. An integrated methodology consisting of prediction of the processing-induced yield stress and finite element simulation of the impact behavior is proposed. The yield stress is first evaluated directly from the temperature history experienced during injection molding process. A strain rate-dependent elastic-plastic model with the modification to combine the influence of processing thermal history is developed to model the mechanical behavior of PC. Finite element simulation for notched Izod impact test is then conducted to analyze the impact behaviors of PC specimens with different thermal histories. Numerical results of the fracture energies are compared with experimental measurement to verify the proposed methodology. In addition, a series of numerical simulations are performed to examine the influence of thermal history experienced during injection molding on the plastic deformation and fracture energy of PC specimens.