Short, Sharp, Shock-- High Strain Rate Material Testing
Under routine operating conditions, many structural materials are sub-jected--either by accident or design--to high rates of loading, which can cause catastrophic failure or corresponding high rates of straining. In numerous practical engineering situations, from the everyday traffic accident to the impact of runway debris on aircraft composite panels, large strains are applied in milliseconds.
At high-strain rates, the mechanism by which many materials deform is different from that experienced at lower rates, and many material properties are strain-rate sensitive. Consequently, quasi-static stress-strain data may not produce accurate predictions at high-strain rates, and the use of such data in the analysis and design of dynamically loaded structures can lead to designs of parts that are too heavy or prone to premature structural failure. It is essential that the material's deformation characteristics under high-strain conditions are understood so the engineer can make appropriate design choices.