Multiscale model to study dislocation dynamics in nonlinear resonance spectroscopy of crystalline solids.

This letter reports on a multi-scale model which captures the dislocation dynamics due to applied vibration stress and its influence on the bulk nonlinear response in a nonlinear resonance spectroscopy experiment. Due to dislocation dynamics, a sinusoidal variation in frequency shift could be observed at the low applied stress range, which was consistent with NRS experiments carried out on cold drawn steel. Using the model, NRS response to "Buck hook" phenomenon was also explored. The results showed that the frequency shift can exhibit three strain regions similar to non-classical nonlinear materials. Further discussions highlight the non-classical nonlinear nature of crystalline solids with lattice defects.