[SY-G3] Symposium G-3

[SY-G3] Branched Hugoniot curve of aluminum in strong shock using molecular dynamics

^○Jimin Choi¹, Sanghyuk Yoo¹, Soonho Song¹, Jung Su Park², Keonwook Kang¹ (1.Yonsei Univ., Korea, 2.Agency for Defense Development, Korea)

Two different embedded-atom method(EAM) potentials were used in single crystalline FCC Al : WKG (J.M. Winey, Alison Kubota, and Y.M. Gupta), and FWYD (Qin-Na Fan, Chong-Yu Wang, Tao Yu, Jun-Ping Du). A 300k single crystalline Al system is inflicted planar shock at an adiabatic condition of 0.1 to 3.0 km/s. Pressure, volume and temperature profiles are obtained after shock as impact velocity. We extract the principle Hugoniot curve in averaged value of profiles. Branch points are selected on the principle Hugoniot curve. We made an isentropic equilibrium system that approximates branch points. The isentropic equilibrium system is inflicted planar shock to impact at an adiabatic condition of 0.1 to 3.0 km/s to obtain the branched Hugoniot curve. It is observed that either stacking fault formation or phase transformation from FCC to HCP or FCC to BCC occurs depending on the potential model. This study shows how the branched Hugoniot curve of single crystalline aluminum differs from the principle Hugoniot curve in strong shock. In addition, by analyzing the differences according to potential models, we show that the potential model must be carefully selected in the strong shock simulation.