Strain rate dependent mechanical behavior of glass fiber reinforced polypropylene composites and its effect on the performance of automotive bumper beam structure

Abstract

In this study, the strain rate dependent mechanical behavior of glass fiber reinforced thermoplastic polypropylene (GFPP) was investigated under the high strain rate. The split Hopkinson pressure bar (SHPB) apparatus was used in order to investigate the effects of strain rate based on the dynamic tensile, compressive and bias-extension shear behavior. The failure mode in fracture surface of each specimen was analyzed by using the scanning electron microscopy with respect to the strain rate. Additionally, the impact simulation of bumper beam was conducted to verify the measured strain rate dependent mechanical behavior of GFRP by using the commercial finite element analysis software LS-Dyna. Finally, it was found that the impact response of GFRP structures could be accurately predicted by using the strain rate dependent mechanical behavior compared to those of quasi-static properties.