A Report on the use of Weak-Shock Wave Profiles and 3-D Dislocation Dynamics Simulations for Validation of Dislocation Multiplication and Mobility in the Phonon Drag Regime

Cazamias, J ; Lassila, D ; Shehadeh, M ; Zbib, H

Lawrence Livermore National Laboratory

关键词: Compression;    Phonons;    Strain Rate;    Dislocations;    Simulation;   

DOI  :  10.2172/15013922
RP-ID  :  UCRL-TR-202511
RP-ID  :  W-7405-ENG-48
RP-ID  :  15013922

美国|英语

来源: UNT Digital Library

【 摘 要 】

Dynamically loaded gas gun experiments were performed to validate the predictive capabilities of 3-D dislocation dynamics (DD) code simulations at very high strain rates and dislocation velocities where the phonon drag mechanism will be dominant. Experiments were performed in the weak-shock regime on high-purity Mo single crystals with [001] compression axes. We have also performed shock-recovery experiments and are in the process of analyzing the dislocation structure generated by the weak-shock using transmission electron microscopy (TEM), which will also be used to validate the dislocation structure predicted by the DD simulations. The DD simulations being performed at Washington State University by Prof. H. Zbib and co-workers will be compared to the experimentally measured wave profiles, thereby validating mechanisms of dislocation generation and motion. Some DD simulation results are presented to demonstrate the feasibility of using a combined experimental/simulation effort for the validation of dislocation generation and mobility physics issues in the phonon drag regime.