Three-dimensional dislocation dynamics simulations of cyclic deformation in FCC metals

摘要

Micromechanisms of fatigue deformation in face-centered cubic (FCC) metals are primarilydue to dislocation motion,storage and annihilation under cyclic loadings.To develop a quantitativerelationship between dislocation processes and fatigue damage accumulation,we use athree-dimensional dislocation dynamics (3D-DD) method to simulate microplasticity in a Cu singlegrain.The 3D-DD method used here can directly simulate the behavior of each individualdislocation and their collections.Cyclic loadings with various amplitudes and frequencies are appliedalong different crystallographic orientations to study how dislocation microstructures evolve.Detailed analysis reveals how grain size affects the formation of microstructure patterns and cyclicbehavior of the grain.