Material Strength Models for Vanadium

We have preliminary results of measurements of vanadium strength at 600 kb and 1 Mb, at strain rates between 10$^{7}$ and 10$^{8}$/s. The results are inconsistent with the Steinberg-Guinan [1] model, which is independent of strain rate, but can be made consistent with other models, such as PTW [2]. We show a variety of different strength models and compare them to the data. [1] DJ.Steinberg, S.G.Cochran, and M.W.Buinan, J. Appl. Phys. \textbf{51}, 1498 (1980). [2] D.L. Preston, D.L.Tonks, and D.C.wallace, J. Appl. Phys. \textbf{93}, 211 (2003). This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.