Publications

Mesoscale modeling and debris generation in hypervelocity impacts

Bouchey, Stephanie N.; Hollenshead, Jeromy H.

This work compared the effects of modeling grain structure in hypervelocity impact simulations. Comparisons of strain rate at failure (fragment size) and material temperature were made between a suite of simulations performed with the standard bulk modeling structure and one in which individual grains were modeled. Smaller fragments or higher temperatures are needed to match EO/IR signatures from observed impacts. Results from the various studies described herein indicate that strain rate at failure is influenced primarily by projectile size, impact velocity, and material porosity. Material temperature is predominantly influenced by impact velocity and porosity; not by projectile size. Changes to the material properties within grains tended to affect lower strain rates only, but material interfaces (here, manifested as material porosity) drastically increased strain rate at failure and material temperatures. Higher strain rates are likely to produce smaller debris fragments, which, along with hot debris may help provide evidence supporting the generation of sub-micron fragments currently required by many EO/IR predictive models to successfully compare with observed hypervelocity impacts. Future work will focus on extending the study to three dimensions, assessing more realistic grain aspect ratios, and simulating other types of interfaces such as inclusions and dislocations.