Cyclic Bending Response of Single- and Polycrystalline Thin Films: Two Dimensional Discrete Dislocation Dynamics

摘要

The bending behavior of single- and polycrystalline thin filmsis modeled by two-dimensional discrete dislocation dynamics (DDD) to study the cyclic bending response. In the polycrystalline films, grain boundaries (GBs) are simulated with a penetrable dislocation-GB interaction model. Our results reveal that thesingle- and polycrystalline thin films under pure bending exhibit strong Bauschinger effect but no cyclic hardening or softening. Furthermore, the uploading response of each cycle can be divided into three stages, which are associated with the glide, annihilation and nucleation of dislocations, respectively.