2018/07/11 by P. C. N. Pereira, Pereira, P. C. N., S. W. S. Apolinario +1
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Force Microscopy Techniques and Applications #High-pressure geophysics and materials #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Microstructure and mechanical properties #Nonlocal and gradient elasticity in micro/nano structures #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.1807.04321
openalex publication_date 2018/07/11 · openalex created_date 2022/08/04 · openalex updated_date 2026/07/28
Dislocations are topological defects known to be crucial in the onset of\nplasticity and in many properties of crystals. Classical Elasticity still fails\nto fully explain their dynamics under extreme conditions of high strain\ngradients and small scales, which can nowadays be scrutinized. In such\nconditions, corrections to the Volterra dislocation fields and to the\nPeach-Koehler force, for example, become relevant. One way to go beyond the\nVolterra solution is to consider other terms in the total Laurent series\nsolution. This is the so called core field. One of its consequences is to\npredict a driving force on the dislocation due to background strain/stress\ngradients, which has also been suggested by other core energy calculations.\nHere we confirm its existence by presenting a direct observation of strain\ngradients driving edge dislocations in 2D atomistic simulations. We show that,\nin systems with scale invariance, the results for such core force can be used\nto obtain the total core energy, allowing a standard value for this energy to\nbe compared with other classical methods of obtaining it. The force measured in\nour system differs from the prediction obtained by a direct core field\nanalysis. Moreover, we found that higher order gradients of strains can also\nact as relevant forces.\n