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Free keywords:
Mechanical engineering; Models; Plasticity, Analytic formula; Convergence test; Dislocation mobility; Empirical parameters; Input parameter; Peierls-Nabarro model; Sensitivity; Standing problems, Single crystals
Abstract:
The sensitivity in predicting glide behaviour of dislocations has been a long-standing problem in the framework of the Peierls-Nabarro model. The predictions of both the model itself and the analytic formulas based on it are too sensitive to the input parameters. In order to reveal the origin of this important problem in materials science, a new empirical-parameter-free formulation is proposed in the same framework. Unlike previous formulations, it includes only a limited small set of parameters all of which can be determined by convergence tests. Under special conditions the new formulation is reduced to its classic counterpart. In the light of this formulation, new relationships between Peierls stresses and the input parameters are identified, where the sensitivity is greatly reduced or even removed. © 2018 Elsevier Ltd.
