Abstract: To simulate the mechanical behavior of the FCC crystal with the lower Peierls stress, the stiff property and physical meaning of the differential equation group consisted of dislocation evolution and mechanical state based on the 3-D discrete dislocation dynamics, the results indicate that the differential equation group is serious stiff, namely the external stress changes more quickly than dislocation evolution. Using the established numerical algorithm, we simulate the mechanical behavior of FCC crystal with the dislocations located in the parallel slip planes, and discuss the effect of strain rate on the dislocation configuration and mechanical behavior, and the saturation process of mobile dislocation. The simulation results indicate that our numerical algorithm can efficiently simulate the dislocation dipole and the low strain rate loading.

Key words: FCC crystal, Mechanical behavior, Dislocation dynamics, Numerical simulation