dislocations

Amit Acharya and Robin J. Knops

(to appear in Journal of Elasticity)

The common practice of ignoring the elastic strain gradient in measurements of geometrically necessary dislocation (GND) density is critically examined. It is concluded that the practice may result in substantial errors. Our analysis points to the importance of spatial variations of the elastic strain field in relation to its magnitude in inferring estimates of dislocation density from measurements.

Acharya, A., Jump conditions for GND evolution as a constraint on slip transmission at grain boundaries, Philosophical Magazine, 87(8-9), 1349-1359, 2007 (see attachment)

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).

My co-organizers and I invite you to submit an abstract to the upcoming symposium “Multiscale Perspectives on Plasticity in Metals” at the ASME 2012 International Mechanical Engineering Congress & Exposition (IMECE), to be held November 9-15, 2012 in Houston, Texas. This symposium will explore the unique challenges to understanding plastic deformation in metals and formulating material models that can accurately predict thermo-mechanical deformation.

We anticipate the opening of four postdoctoral positions in 2012 to work on statistical aspects of fracture and plasticity,  and in particular on size effects in the fracture of  disordered media and in microplasticity.  The positions will be funded by the ERC Advanced Grant 2011, SIZEFFECTS.



We look for candidates with a strong background in one or more of the following areas:

- statistical mechanics (scaling, critical phenomena, disordered systems)

- numerical modeling fracture

- dislocation dynamics simulations