A stochastic dislocation dynamics (SDD) model is developed to investigate dislocation glide through dispersed obstacles. The model accounts for: 1) the dynamics of the flight process between successive meta-stable dislocations under various drag mechanism using discrete dislocation dynamics, and 2) thermal activation processes for meta-stable pinned dislocations using a stochastic force. The integration of the two processes allows one to examine the transient regime of dislocation motion between obstacle-controlled motion and drag-controlled motion. Result pertaining to the stress-strain rate behavior in copper are obtained. The stress and temperature dependence of the average dislocation velocity show obstacle-controlled region below the critical resolved shear stress (CRSS) and drag controlled region above the CRSS, which is in good qualitative agreement with experimental data. In the transient region right below the CRSS, negative temperature sensitivity is observed due to the competition between the drag effects in dislocation flight process and thermal activation process.
Stochastic Dislocation Dynamics for Dislocation-Defects Interaction: A Multiscale Modeling Approach
Contributed by the Materials Division for publication in the JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY. Manuscript received by the Materials Division February 19, 2002; revised manuscript received March 8, 2002. Guest Editors: Tariq A. Khraishi and Hussein M. Zbib.
- Views Icon Views
- Share Icon Share
- Search Site
Hiratani, M., and Zbib, H. M. (June 10, 2002). "Stochastic Dislocation Dynamics for Dislocation-Defects Interaction: A Multiscale Modeling Approach ." ASME. J. Eng. Mater. Technol. July 2002; 124(3): 335–341. https://doi.org/10.1115/1.1479693
Download citation file: