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Crystal plasticity

Soud Choudhury's picture

Need help for running UMAT of Dr. Huang's single crystal

Hello Everyone,

I am a new member of imechanica. I have started to learn UMAT of Abaqus to model my material behavior ( Cu6Sn5, HCP) using crystal plasticity finite element model. I found Dr. Huang's single crystal UMAT to start learning UMAT and I thought that it would be a great guide to start though it is written for FCC mat. But unfortunately I was not able to run the UMAT with it's input file.

Position within ERC Strarting Grant MINATRAN in Univ of Erlangen

There is a postdoctoral research postition within Dr. K.E. Aifantis's ERC Starting Grant at the Univ of Erlangen. The project is concerned with examining dislocation_interface interactions through gradient plasticty and simulations. A PhD in materials engineering is required and publications in the field must be evident. If a good experimental candidate is found who can perform in situ TEM/nanoindentation experiments he/she will also be considered. The position needs to be filled asap and can be extended for 18 months.

Siddiq Qidwai's picture

Determination of Representative Volume Element (RVE) based on Microstructure

Estimating the response of polycrystalline materials using sets of weighted statistical volume elements

Siddiq M. Qidwai, David M. Turner, Stephen R. Niezgoda, Alexis C. Lewis, Andrew B. Geltmacher, David J. Rowenhorst, Surya R. Kalidindi

Acta Materialia, 60, 5284–5299, 2012; 

Postdoc opportunity in the field of computational mechanics


New Technologies Research centre at the University of West Bohemia (Czech Republic) invites applications for a Postdoctoral position in the field of Computacional Mechanics of Materials. Highly motivated individuals holding a PhD in Mechanics, Materials Science or closely related fields are encouraged to apply.

A crystal plasticity continuum theory with length scale dependent internal residual stress and free surface effect

The long range elastic interaction between dislocations is naturally accounted in
discrete dislocation plasticity through stress field of individual dislocation.
In addition, the dislocation boundaries elastic interaction is considered via
image stress superposition approach in the finite element framework. In current
study these interaction terms are considered in crystal plasticity framework
through length scale dependent internal residual stresses which are arise from

Mubeen's picture

Advanced Finite Plasticity Textbooks

While reading the article

"An alternative approach to finite plasticity based on material isomorphisms " (1999) by Prof. Bertram, the first thing that attracted my attention was the quote [by Prof. Naghdi (late)]:

 “there is some degree of disagreements on nearly all of the main constitutive ingredients and features of plasticity in the presence of finite deformation... Some of the issues of disagreements are of basic and fundamental importance.”

Tuncay Yalcinkaya's picture

Full scholarships available at European Commission funded workshop on physically based material modeling

European Commission' s JRC (Joint Research Centre) is organizing a workshop on physics based modeling of material properties and experimental observations in collaboration with METU (Middle East Technical University). The workshop will be held in Ankara on 22-23 October 2012.

The Workshop will include lectures by keynote speakers: W. Curtin, F. Dunne, L. Malerba, J-F Molinari, A. Needleman and B. Svendsen, and presentations by participants (oral or posters).


The objective of the workshop, co-organized by Joint Research Centre of the European Commission and Middle East Technical University, is to discuss the present status of physics based constitutive modelling of metallic materials and associated experimental methods.

The Workshop is funded by the European Commission's Integration and Enlargment Programme.  There is no cost for attending the Workshop. A limited number of scholarships is available for participants from the target countries (see attached flyer).

Post-doctoral position on Crystal Plasticity Modelling of Deformation in Hexagonal Metals

A full-time post as a LATEST2 Research Associate is available for a 2 year fixed term subject to relevant skills and experience to work as part of the LATEST2 (Light Alloys Towards Environmentally Sustainable Transport: 2nd Generation) team in the School of Materials, University of Manchester. 

Post-Doc/PhD in mechanics of grain boundaries at Max-Planck-Institut für Eisenforschung, Düsseldorf

MPI für Eisenforschung, Düsseldorf, Department for Microstructure Physics and Alloy Design
Post-Doc or PhD Position: Characterizing and modeling the mechanics of crystalline interfaces

Research Scientist at TU Bergakademie Freiberg

A research scientist position is available at TU Bergakademie Freiberg in the area of computational modeling of dislocation properties using either molecular dynamics, discrete dislocations or crystal plasticity. The research of the group focuses on dislocation properties at both the nanoscale and the microscale. The successful candidate should have a strong background in numerical modeling with demonstrated capability of innovative and independent research.

Postdoctoral Position in Solid Mechanics

The Department of Industrial Engineering at the University of Pittsburgh anticipates an opening for a postdoctoral associate starting January 2012. The position’s primary area of research will focus on mechanics of micro-scale deformation processes and characterizing the thermomechanics of deformation at micrometer length-scales. Applicants with a strong background in computational solid mechanics and crystal plasticity will be preferred. 

Postdoctoral postion in multiscale computational mechanics at RPI

There is an immediate opening for a postdoctoral research position in the Advanced Computational Research Laboratory at RPI, Troy NY to work on Multiscale Computational Mechanics. Encouraged to apply are creative, self-motivated candidates with a sound background in computational mechanics. RPI is home to the CCNI, one of the most powerful university-based super-computational research facilities in the world.

Combining UMAT with XFEM

Hi all,
I 'd like to ask whether anyone has applied XFEM for a user-material (UMAT). What is the process to do that? Could anyone provide some advice, documentation or guidelines?

All the best,

p.s. I 've heard that a UEL code is needed to couple XFEM with UMAT.

problem using crystal plasticity model in Abaqus via UMAT

I am trying to model polycrystal behaviour using Abaqus Umat via crytalplasticity . My Umat results for single crystal & about 5 grain, are reasonable, but when, I try to use more than 5 grain in each integration point  (polycrystal model) abaqus aborted with following message after about 15 increment:

Abaqus Error: The executable C:\SIMULIA\Abaqus\6.10-1\exec\standard.exe aborted with system error code 693...


I will be happy if someone guide me about this problem.

Voronoi tesselation

Dear all,

      I would like to ask you how is it possible to import into abaqus a 2-D or a 3-D Voronoi structure. so far I ve been able to create my grains into Matlab or fortran but I dont know how to import them into abaqus.

All the best,


Mubeen's picture

CISM Course: Plasticity and Beyond

Dear all,

please find information about the 5 day - course on Plasticity and Microstructures at CISM Udine, Italy.

The link is:

Flyer is attached.

Best regards,



Original post from CISM website:

Plasticity and Beyond: Microstructures, Crystal-Plasticity and Phase Transitions

UMAT code for crystal plasticity

Dear all,

           I would like to ask you something about prof.
Huang's subroutine. I want to verify the code, by using published
stress-strain data. But when I am plotting my stress -strain curve I am
always getting a straight line instead of a curve that shows the hardening effect. What could be a reason for this problem?



p.s. I am using a single crystal, single element, and only modify the crystal orientation

Voronoi tesselation-grain size and orientation

Dear all,

         I am trying to produce a metallic grain structure  using Voronoi. I am currently using Matlab. Does anyone know how I can control the area of the polygons-grains (impose a Gaussian distribution)? And another point is how can I assign the grain orientation for every polygon?



PhD position - Modelling of confinement and interfacial effects in small scale plasticity

The project is based on the well-known size effect exhibited by metals, i.e
the fact that their strengths are greatly enhanced when at least one
microstructural lengthscale is scaled down to the nanometer range or
when the size of the object is restricted to the micron or sub-micron
range. At these scales the interfaces and their associated properties
play a significant role. This project will focus on the effect of
spatial confinement on the three most common deformation mechanisms:
dislocation glide, mechanical twinning and mechanically-induced
martensitic phase transformations; and will be based on the synergies
between physically-based phenomenological modelling using
strain-gradient plasticity at the highest scale, and thorough

Shunlai.Zang's picture

Question on the visualization softwares of texture.

Hi everyone,

I want to know if there are some opensource softwares to transfer the x-ray raw data to representative discrete pole figure data by Euler angles ? Now I know how to calculate ODF from x-ray raw data with the help of "Mtex". But I dont know how to get representative discrete pole figure data by Euler angles, which is used for CP numerical simulation, from ODF.

Thank you very much!



I am getting an error while running Single crystal UMAT of Huang



this is a error which pops out when i try to run Huang's single crystal UMAT. Do anybody have experienced the same kind of error




Justin C. Mach's picture

Continuity in the Plastic Strain Rate and its Influence on Texture Evolution

Classical plasticity models evolve state variables in a spatially independent manner through (local) ordinary differen- 

tial equations, such as in the update of the rotation field in crystal plasticity. A continuity condition is derived for the 

lattice rotation field from a conservation law for Burgers vector content—a consequence of an averaged field theory 

of dislocation mechanics. This results in a nonlocal evolution equation for the lattice rotation field. The continuity 


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