@Article{cmes.2021.016756, AUTHOR = {Yuxi Xie, Shaofan Li}, TITLE = {Geometrically-Compatible Dislocation Pattern and Modeling of Crystal Plasticity in Body-Centered Cubic (BCC) Crystal at Micron Scale}, JOURNAL = {Computer Modeling in Engineering \& Sciences}, VOLUME = {129}, YEAR = {2021}, NUMBER = {3}, PAGES = {1419--1440}, URL = {http://www.techscience.com/CMES/v129n3/45695}, ISSN = {1526-1506}, ABSTRACT = {The microstructure of crystal defects, e.g., dislocation patterns, are not arbitrary, and it is possible that some of them may be related to the microstructure of crystals itself, i.e., the lattice structure. We call those dislocation patterns or substructures that are related to the corresponding crystal microstructure as the Geometrically Compatible Dislocation Patterns (GCDP). Based on this notion, we have developed a Multiscale Crystal Defect Dynamics (MCDD) to model crystal plasticity without or with minimum empiricism. In this work, we employ the multiscale dislocation pattern dynamics, i.e., MCDD, to simulate crystal plasticity in body-centered cubic (BCC) single crystals, mainly α-phase Tantalum (α-Ta) single crystals. The main novelties of the work are: (1) We have successfully simulated crystal plasticity at micron scale without any empirical parameter inputs; (2)We have successfully employed MCDD to perform direct numerical simulation of inelastic hysteresis of the BCC crystal; (3) We have used MCDD crystal plasticity model to demonstrate the size-effect of crystal plasticity and (4) We have captured cross-slip which may lead to size-effect.}, DOI = {10.32604/cmes.2021.016756} }