Internal stress evolution in Fe laths deformed at low temperature analysed by dislocation dynamics simulations

ABSTRACTIn order to study the dislocation density evolution of body centered cubic (bcc) crystals at low temperature by dislocation dynamics (DD) simulations, we investigated carefully three different boundary conditions (BC) for DD, i.e., the quasi-free surface BC, the flux-balanced BC, and the periodic BC. The latter two BCs can account for the dislocation loss from the boundary of the finite simulation box. PBC can also eliminate the influence of surfaces and improve the line connectivity. We have found that the PBC provides a convenient and effective boundary condition for DD simulations and have applied it to the study of dislocation density evolution of bcc metals during stage 0 deformation at low temperature.

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Dislocation dynamics simulations of plasticity in Fe laths at low temperature

Acta Materialia ◽

10.1016/j.actamat.2008.07.047 ◽

2008 ◽

Vol 56 (19) ◽

pp. 5466-5476 ◽

Cited By ~ 31

Author(s):

Julien Chaussidon ◽

Christian Robertson ◽

David Rodney ◽

Marc Fivel

Keyword(s):

Low Temperature ◽

Dislocation Dynamics ◽

Dynamics Simulations

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Molecular dynamics simulations of internal stress evolution in ultrathin amorphous carbon films subjected to thermal annealing

Thin Solid Films ◽

10.1016/j.tsf.2020.138247 ◽

2020 ◽

Vol 713 ◽

pp. 138247

Author(s):

Shengxi Wang ◽

Kyriakos Komvopoulos

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Internal Stress ◽

Thermal Annealing ◽

Amorphous Carbon ◽

Carbon Films ◽

Stress Evolution ◽

Amorphous Carbon Films ◽

Dynamics Simulations

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Plastic Ploughing of a Sinusoidal Asperity on a Rough Surface

Journal of Applied Mechanics ◽

10.1115/1.4030318 ◽

2015 ◽

Vol 82 (7) ◽

Cited By ~ 11

Author(s):

H. Song ◽

R. J. Dikken ◽

L. Nicola ◽

E. Van der Giessen

Keyword(s):

Friction Stress ◽

Dislocation Dynamics ◽

Two Dimensional ◽

Unit Process ◽

Contact Models ◽

Self Similar ◽

Dynamics Simulations ◽

Micrometer Scale ◽

Edge Dislocations ◽

Flat Contact

Part of the friction between two rough surfaces is due to the interlocking between asperities on opposite surfaces. In order for the surfaces to slide relative to each other, these interlocking asperities have to deform plastically. Here, we study the unit process of plastic ploughing of a single micrometer-scale asperity by means of two-dimensional dislocation dynamics simulations. Plastic deformation is described through the generation, motion, and annihilation of edge dislocations inside the asperity as well as in the subsurface. We find that the force required to plough an asperity at different ploughing depths follows a Gaussian distribution. For self-similar asperities, the friction stress is found to increase with the inverse of size. Comparison of the friction stress is made with other two contact models to show that interlocking asperities that are larger than ∼2 μm are easier to shear off plastically than asperities with a flat contact.

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