Plasticity

Stefan C. Soare's picture

Plastic Spin

In the classical (rate-independent)
theory of metal plasticity, the plastic spin has been an issue of
research and debate for about thirty years. Judging by the content
of current publications on the topic (regarding modeling
possibilities, consequences and applications), it seems that the
concept has acquired a certain degree of acceptance, although no
rigorous justification, at theoretical level, has ever been provided.
In the attached preprint this matter is investigated starting from
crystal level and going up to the macro-level (of an aggregate of
many crystals) by employing Hill's averaging techniques and his
differential invariant.


WaiChing Sun's picture

PhD position in computational poromechanics at Columbia University

The computational poromechanics laboratory in the Civil Engineering and Engineering Mechanics Department is seeking a PhD candidate for Fall 2014 semester. The sucessful candidate should have (1) a master degree in applied mechanics, geomechanics or related disciplines, (2) a strong background in engineering mathematics, continuum mechanics, finite element method and computational plasticity, (3) be proficient in C++ and FORTRAN code developments and (4) possess excellent communication skills. Knowledge in discrete element/attice Boltzmann method, geostatistics and multiscale modeling is a plus.


Varying Yield Strength through depth in Abaqus

Hi,

I am trying to create a material model in Abaqus such that I have a varying yield strength through the depth (y-coordinate). I want a model which has maximum yield strength at the top surface and gradually goes on decreasing with y-coordinate. Is there a way to do this? Any help/insight would be greatly appreciated. Thank you.

Regards,

Deepak Patil


Dabiao Liu's picture

Anomalous plasticity in the cyclic torsion of micron scale metallic wires

Our new paper entitled "Anomalous
plasticity in the cyclic torsion of micron scale metallic wires" has been
accepted by PRL

(see: http://link.aps.org/doi/10.1103/PhysRevLett.110.244301)


Defining plasticity in ABAQUS

Hi all,

I am using Abaqus to simulate the behavior of a steel connection using a Static,General analysis. For bolts, the last values ​​for yield stress and plastic strain are 1 and 0.05, respectively.After running the model, I get values ​​of equivalent plastic strain in the bolts of 0.15.

Why do I get values ​​that are higher than the ones I define? Shouldn't I get a maximum of 0.05?  What can I be doing wrong?

Thank's,

Paulo Freitas


Marisol Koslowski's picture

Post-Doctoral Opening on Multiscale Modeling of Materials

We are seeking to hire outstanding candidates for a post-doctoral research position in

the Koslowski’s group at Purdue University to work on dislocation dynamics and/or

continuum modeling of plasticity. The project involves developing and applying

numerical methods to study creep and plastic deformation in nano and ultrafine

crystalline materials. Successful candidates will have the opportunity to interact with a


Ansys divergence

Hello All,

I have a question regarding Ansys solution divergence in nonlinear static analysis, with geometry and material nonlinearities. In this case the model is shell but that should ba valid for bricks as well.


Material Modelling

Hi all,

      I doing modelling on soft clay behaviour which exhibit softening behaviour during constant strain loading. Here i followed a non-associated flow rule for better prediction of dilation . For the case of non-associated flow rule yield function and plastic potential function should not same i clear in that , my doubt is that we can use two different surface for yield and plastic potential function (eg: linear surface as yield surface and elliptical surface as plastic potential )? 


Imme's picture

Analytical elastic-plastic solutions for the torsion of a round bar with a heterogeneous cross section


Hello,


I am trying to derive/find an analytical expression
for the torsion of a round bar made of an heterogeneous material. But I just do
not seem to find any solution available in the literature other than for a
homogeneous material, which can be find in any theory of plasticity book (e.g.
Theory of Plasticity, 3rd Ed., J. Chakarabarty, pp. 132-136).


Orthotropic plasticity model

Dear all,

Is there any one of you know a material model which can reflect the orthotropic , hysteresis, and load ratio dependence behaviors? 

Every helps would be highly appreciated.

 

Kindest regards,

Ken Dinh 


Kyriakos Kourousis's picture

Mini-symposium 'Cyclic Plasticity Models for Sheet Metal Forming' - NUMISHEET 2014

Dear Colleagues,

I would like to invite to you to submit an abstract to the mini-symposium on 'Cyclic Plasticity Models for Sheet Metal Forming' at the 9th International Conference on Numerical Simulation of 3D Sheet Metal Forming Processes (NUMISHEET) to be held at Melbourne - Australia January 6-10, 2014 (http://www.numisheet2014.org). 


Oden Warren's picture

Nanobrücken-Dresden Nanomechanical Testing Workshop


Dear Colleague, we cordially invite you to participate in the Nanobrücken-Dresden Nanomechanical Testing Workshop at TU Dresden (Mar 20, 2013) and Fraunhofer IZFP Dresden (Mar 21-22, 2013). The workshop's main theme is nanomechanical testing applied to advanced materials and semiconductor devices, but the workshop is open to all aspects of nanomechanical research including in-situ experimentation and theory/simulation. The Call for Abstracts (Feb 8, 2013 submission deadline) and registration information can be found at the workshop's updated website: http://hysitron.com/nbdresden.


jelawady's picture

Pre-straining effects on the power-law scaling of size-dependent strengthening in Ni single crystals

Pre-straining effects on the power-law scaling of size-dependent strengthening in Ni single crystals

Jaafar A. El-Awady, Michael D. Uchic, Paul A. Shade, Sang-Lan Kim, Satish I. Rao, Dennis M. Dimiduk, Christopher Woodward

 

Volume 68, Issues 3–4, February 2013, Pages 207–210

 


Piriform yield surface

Piriform yield surface
Dan Gianola's picture

Variable Plasticity in Metallic Glass Nanowires

Tunable Tensile Ductility in Metallic Glasses

D.J. Magagnosc, R. Ehrbar, G. Kumar, M.R. He, J. Schroers, D.S. Gianola

Scientific Reports 3 (2013) 1096 


Nonlinear Dynamics - 2013. Registration deadline extended till January 28th

Dear Colleagues,


The new deadline for abstract (plain text, 400 word limit) submission is now January 28, 2013.

 

The 4th conference "Nonlinear Dynamics -2013" will be held from 19 until 22 June, 2013 in Sevastopol (Ukraine).

Conference web-site: https://sites.google.com/site/ndkhpi2013/home

  

The conference is organised by:

  • National Technical University "KhPI" (Kharkov, Ukraine)
  • McGill University (Montreal, Canada)
  • Institute of Mechanics, National Academy of Sciences of Ukraine (Kiev, Ukraine) 

 


Amit Acharya's picture

An observation on the experimental measurement of dislocation density

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.


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