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Research Scientist Positions on Computational Mechanics/Solid Mechanics at Institute of High Performance Computing, A*STAR Research Entities, Singapore

We seek candidates with good research experience in computational mechanics, solid mechanics, and plasticity theory. The candidate is to use computational modeling to study the dislocation-mediated microstructure evolution and material behavior in various manufacturing processes.

The desired candidate will have:

·   Ph.D. in Mechanical Engineering / Solid Mechanics / Material Science

·   Solid background in the mechanics of materials, nonlinear continuum materials, dislocation theory of plasticity of metals

Erik Bitzek's picture

Three Ph.D. Positions in Computational Atomistic Modeling

The Department of Materials Science and Engineering of the Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg is inviting applications for three doctoral research positions to begin immediately. The successful applicants will work together with Prof.

rbsills's picture

Postdoc Opening in Computational Materials Science at Rutgers University

The microMechanics of Deformation Research Group (mMOD) in the Department of Materials Science and Engineering at Rutgers University is seeking a Post-Doctoral Associate to participate in a pair of collaborative projects with a Department of Energy National Laboratory. The projects are focused on using discrete dislocation dynamics (DDD) simulations to understand dislocation patterning in deformed metals, and molecular dynamics (MD) simulations to understanding crack initiation in hydrogen-affected steels.

Yizhe_Tang's picture

Inertia of Dislocation Motion and Negative Mechanical Response in Crystals

Dear Colleagues,

Please see attached a recent article published in Scientific Reports on the fundamental nature of dislocation motion in crystals. Leave your comments or whatever you think of it.

Link: https://www.nature.com/articles/s41598-017-18254-5

 

Best,

Is it safe to assume that the change in a dislocations' burger's vector size is negligible during loading?

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As a result of loading, there is grain distortion, which results in lattice distortion. when lattice distortion happens, then lattice parameter changes. The change in lattice parameter, (a), results in a dislocation's burger's vector size change, since it has the lattice parameter size in its formula. Consequently, one can conclude that the size of burger's vector of a dislocation changes as a result of loading! . Still, is it practically safe to assume that the the change in its size is negligible compared to its initial size before loading?

Is there a way to measure the magnitude of a dislocation burger's vector via high precision optical microscopes?

I need to calculate the size or magnitude of the burger's vector of a dislocation in crystalline materials, metals. Obviously and typically, it can be measured via XRD or the electron microscopy methods, TEM and SEM. The question is:

could it also be measured via high precision optical microscopes, as precise as 1nm ?

mohsenzaeem's picture

Competing mechanisms between dislocation and phase transformation in plastic deformation of single crystalline yttria-stabilized tetragonal zirconia nanopillars

Molecular dynamics (MD) is employed to investigate the plastic deformation mechanisms of single crystalline yttria-stabilized tetragonal zirconia (YSTZ) nanopillars under uniaxial compression. Simulation results show that the nanoscale plastic deformation of YSTZ is strongly dependent on the crystallographic orientation of zirconia nanopillars. For the first time, the experimental explored tetragonal to monoclinic phase transformation is reproduced by MD simulations in some particular loading directions.

Harley T. Johnson's picture

A critical thickness condition for graphene and other 2D materials

B. C. McGuigan, P. Pochet, and H. T. Johnson, Critical thickness for interface misfit dislocation formation in two-dimensional materials, Phys. Rev. B 93, 214103, 2016.

URL: http://link.aps.org/doi/10.1103/PhysRevB.93.214103

In Situ Atomic-Scale Observation of Twinning Dominated Deformation in Nanoscale Body-Centred Cubic Tungsten

In situ atomic-scale observation of twinning-dominated deformation in nanoscale body-centred cubic ​tungsten

By Jiangwei Wang, Zhi Zeng, Christopher R. Weinberger, Ze Zhang, Ting Zhu & Scott X. Mao

Nature Materials (2015) doi:10.1038/nmat4228

Ting Zhu's picture

Surface dislocation nucleation

 

  Surface dislocation nucleation

Ting Zhu, Ju Li, Amit Samanta, Austin Leach and Ken Gall, “Temperature and strain-rate dependence of surface dislocation nucleation”, Physical Review Letters, 100, 025502 (2008).

Cai Wei's picture

Dislocations 2008 International Conference

We are pleased to announce Dislocations 2008, an international conference on the fundamentals of plastic deformation and other physical phenomena where the dislocations play pivotal roles.  The conference will take place on October 13-17, 2008 at the Gold Coast Hotel, Hong Kong, China.  More information about the Dislocations 2008 conference can be found at the following web site:

Kejie Zhao's picture

Question: Is the local energy dictating dislocation emission constant for single crystal?

Hi everyone, in my size dependence study, I find the local energy dictating dislocation emission is almost constant for varied sized samples, in given directions of single crystal. I don't know this is an interesing finding, or just a common sense. Will you give me some suggestion, Thank you!

Kejie

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