Dynamic Loading Characteristics in Metals and Composites

This study investigates the mechanical characteristics of aluminum alloy AA3003-H14 when it is subjected to dynamic axial loads at low strain rates of less than 1 s-1. The tensile experiments show that both the ultimate and yield stresses, as well as the absorbed strain energy, increase with strain rate. Moreover, the strains at yield, ultimate load and fracture show positive sensitivity to strain rate. On the other hand, when the material is subjected to dynamic loading rates of more than 10-1 s-1, the elastic modulus
diminishes as the strain rate increases, while both normalized yield and ultimate stresses increase noticeably. It is also appreciated that the amount of plastic strain energy accumulated in a ductile material in its loading time history is useful as a failure criterion for the prediction of failure. Finally, a failure criterion is proposed for loading with varying strain rates.