Failure of Ductile Materials Subject to Varying Strain Rates

Strain rate affects the mechanical properties of ductile materials in terms of their stiffness and strength. In particular, yield and failure strengths and strains depend on the strain rate applied to the materials. When a metallic material is subjected to a typical dynamic loading, the material usually undergoes various strain-rate loading conditions. One of the main questions is whether the material is going to fail or not. To the authors' best knowledge, there has been no failure criterion proposed for a varying strain-rate loading condition. This paper presents a failure criterion under nonuniform strain-rate loading conditions. Experiments were conducted to support the proposed failure criterion using aluminum alloy AA3003-H14. This study also investigated the that failure envelops in terms of strain rates and the normalized failure strengths. Furthermore, the effects of strain rates on strength and stiffness properties were also examined. [DOI: 10.1115/1.4002054]