Strain rate dependent constitutive behavior investigation of AerMet 100 steel

AerMet 100 exhibits excellent mechanical properties with both high yield strength and excellent ductility. Understanding the dynamic mechanical behavior of the material should clear the road for wider application of AerMet 100 as critical mechanical parts serving in extreme mechanical conditions. In this paper, the strain rate dependency of AerMet 100 is investigated by using Split-Hopkinson pressure bar (SHPB) and also compared with its quasi-static counterpart. Based on the experiment results, a simplified Johnson-Cook model is established to describe the strain rate dependent behaviors and is proved to perform better than Cowper-Symonds model. The validation of the suggested constitutive model is embedded in the finite element analysis and can well repeat the strain wave observed from experiment results. Furthermore, the impact fracture toughness of AerMet 100 is also studied both numerically and experimentally. Finally, a thin-walled tube made of AerMet 100 is numerically simulated and the excellent crashworthiness is proven. Results may enlighten the understanding of dynamic mechanical behavior of AerMet 100 and provide fundamental experiment data for its future engineering applications. (C) 2015 Elsevier Ltd. All rights reserved.