Prediction of the tensile impact behavior of injection molded samples fromquasi-static data

A methodology for predicting the mechanical behavior of injection molded se micrystalline thermoplastics, within a wide range of strain rates and tempe ratures, is proposed in this work. This method is based on data obtained at isothermal low velocity tensile tests and on a phenomenological constituti ve equation that describes the stress as a function of independent and mult iplicative terms of the strain, strain rate and temperature. The effect of the processing conditions on the coefficients of this equation is considere d by evaluating their dependence on thermo-mechanical indices, calculated f rom melt flow simulations. Using a finite element code that has this equati on built-in, it is possible to predict the mechanical behavior of samples i njected with different molding conditions. The extrapolation of the impact properties requires the consideration of the dependence of the material con sistency on the strain rate, which is affected by the sample skin-core stru cture. So, any constitutive equation used to describe the mechanical behavi or of the injection molded samples must consider the distinct contributions of the main microstructural layers.