MD Simulation of Dislocation Behavior in KCl under Shock Compression

MD simulations of dislocation behavior in KCl under uniaxial compression are carried out to discuss the elastoplastic transition under shock compression. The dislocations proceeded along to 45 degrees to the uniaxialy compressed direction due to the displacement of atomic lines. This result is consistent with the VonMises hypothesis that the shear stress along 45 degrees to uniaxial stress is maximum. Simulation results also showed that the stress, which dislocations started to move under the uniaxial compression along the $<$111$>$ axis direction, was larger than other ones along the $<$100$>$ and $<$110$>$ axis directions. These results are qualitatively consistent with the experimental ones that the Hugoniot-elastic limit along the $<$111$>$ axis direction was larger than the others.