journal article·2019-02

A mechanism-based homogenization of a dislocation source model for bending

Severin Schmitt, Markus Stricker, Peter Gumbsch, Katrin Schulz

Acta Materialia· Volume 164
Publisher page

Abstract

Abstract The homogenization of dislocation dynamics including the mechanisms of dislocation nucleation is a great challenge in dislocation based continuum formulations. Due to the loss of the local and temporal resolution in a continuum model, physical nucleation mechanisms have to be incorporated in an average sense. Consequences can be the over- or underestimation of the macroscopic production rate of dislocation density which results in artificial softening or hardening phenomena. In this paper, we derive a mechanism-based homogenization of a dislocation source model based on the theory of critical thickness, which accounts for the relation between the external loading condition and the resulting dislocation density production rate. The formulation is applied to pure and cantilever bending problems, validated in comparison to discrete dislocation dynamics simulations, and discussed for the discrete-continuum transition regime.
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Research context

OpenAlex topics: Microstructure and mechanical properties · Metallurgy and Material Forming · Metal Forming Simulation Techniques

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References (40)

Show source-provided references
1. Mechanical properties of micro-sized copper bending beams machined by the focused ion beam technique10.1016/j.actamat.2005.05.036 ↗
2. Nanoscale gold pillars strengthened through dislocation starvation10.1103/PhysRevB.73.245410 ↗
3. Plasticity in confined dimensions10.1146/annurev-matsci-082908-145409 ↗
4. Micro-bending tests: a comparison between three-dimensional discrete dislocation dynamics simulations and experiments10.1016/j.actamat.2007.12.053 ↗
5. Length-scale effect due to periodic variation of geometrically necessary dislocation densities10.1016/j.ijplas.2012.09.001 ↗
6. Latent hardening size effect in small-scale plasticity10.1088/0965-0393/21/5/055009 ↗
7. One-dimensional dislocations. ii. misfitting monolayers and oriented overgrowth
8. Theory of deformation in small volumes of material10.1098/rspa.2004.1306 ↗
9. Observation of the critical thickness phenomenon in dislocation dynamics simulation of microbeam bending10.1016/j.actamat.2011.11.060 ↗
10. Geometrically necessary dislocations and strain gradient plasticitya dislocation dynamics point of view10.1016/S1359-6462(02)00341-X ↗
11. Spatial correlations and higher-order gradient terms in a continuum description of dislocation dynamics10.1016/S1359-6454(02)00517-7 ↗
12. Non-local crystal plasticity model with intrinsic ssd and gnd effects10.1016/j.jmps.2004.03.007 ↗
13. A three-dimensional continuum theory of dislocation systems: kinematics and mean-field formulation10.1080/14786430600930218 ↗
14. New perspectives in plasticity theory: dislocation nucleation, waves, and partial continuity of plastic strain rate10.1177/1081286507086903 ↗
15. Continuum dislocation dynamics: towards a physical theory of crystal plasticity10.1016/j.jmps.2013.09.012 ↗
16. Initial dislocation structures in 3-d discrete dislocation dynamics and their influence on microscale plasticity10.1016/j.actamat.2008.12.020 ↗
17. Discrete dislocation plasticity: a simple planar model10.1088/0965-0393/3/5/008 ↗
18. A discrete dislocation analysis of bending10.1016/S0749-6419(99)00013-3 ↗
19. Incorporating three-dimensional mechanisms into two-dimensional dislocation dynamics10.1088/0965-0393/12/1/014 ↗
20. An analysis of exhaustion hardening in micron-scale plasticity10.1016/j.ijplas.2007.08.010 ↗
21. A dislocation-dynamics-based derivation of the frank–read source characteristics for discrete dislocation plasticity10.1088/0965-0393/16/7/075002 ↗
22. A comparison of a statistical-mechanics based plasticity model with discrete dislocation plasticity calculations10.1016/S0022-5096(03)00094-2 ↗
23. Multiple slip in a strain-gradient plasticity model motivated by a statistical-mechanics description of dislocations10.1016/j.ijsolstr.2004.10.025 ↗
24. Dislocation-density based description of the deformation of a composite material10.1088/1361-651X/aa7a88 ↗
25. Discrete dislocation simulations of the plasticity of micro-pillars under uniaxial loading10.1016/j.scriptamat.2007.11.031 ↗
26. A new concept for the calculation of the mobile dislocation density in constitutive models of strain hardening10.1002/pssb.200301873 ↗
27. The deformation of plastically non-homogeneous materials10.1080/14786437008238426 ↗
28. Aspects of boundary-value problem solutions with three-dimensional dislocation dynamics10.1088/0965-0393/10/4/306 ↗
29. Study of dislocation reactions and rearrangements under different loading conditions10.1016/j.msea.2005.03.102 ↗
30. High performance computing and discrete dislocation dynamics: plasticity of micrometer sized specimens10.1007/978-3-540-88303-6_36 ↗
31. Homogenization method for a discrete-continuum simulation of dislocation dynamics10.1016/S0022-5096(01)00026-6 ↗
32. From systems of discrete dislocations to a continuous field description: stresses and averaging aspects10.1088/0965-0393/21/8/085006 ↗
33. Internal stresses in a homogenized representation of dislocation microstructures10.1016/j.jmps.2015.08.012 ↗
34. A continuum formulation of stress correlations of dislocations in two dimensions
35. Analysis of dislocation pile-ups using a dislocation-based continuum theory10.1088/0965-0393/22/2/025008 ↗
36. Latent hardening in copper and aluminium single crystals10.1016/0001-6160(80)90162-5 ↗
37. Physical analyses of crystal plasticity by dd simulations10.1016/j.scriptamat.2005.10.066 ↗
38. Plastic flow and dislocation strengthening in a dislocation density based formulation of plasticity10.1016/j.commatsci.2018.04.065 ↗
39. Über die partiellen differenzengleichungen der mathematischen physik10.1007/BF01448839 ↗
40. Importance of dislocation pile-ups on the mechanical properties and the bauschinger effect in microcantilevers10.1557/jmr.2015.49 ↗