Computer simulation of interacting dislocation motion resisted by pointlike barriers

We consider interacting dislocations of like Burgers vectors in glide through random arrays of pointlike barriers. Two configurations are considered: first, many dislocations in the same glide plane; second, many dislocations on parallel glide planes, initially configured in a low‐angle‐tilt boundary. In our simulation, the glide plane(s) are periodic in all directions. In previous work, we determined the dimensionless athermal critical resolved shear stress for a single dislocation. The present results show that the athermal critical resolved shear stress for glide of a system of interacting dislocations τa* is related to that for a single dislocation system τ0* by the equation τa*=τ0* exp{−(π/h)[1/3λ (βc)1/2]1/2}, where h is a dimensionless average dislocation spacing, λ is a dimensionless dislocation line tension, and βc is a dimensionless barrier strength. The resulting dislocation morphologies can be explained in terms of the above parameters. Also, the stability of a moving low‐angle‐tilt boundary c...