I want to simulate loading of 2D RVE of dual phase steels, by giving individual phases properties, to get homogenised mechanical properties like yield strength, % elongation etc, using micromechanics based approach. Litterature shows people have used two kinds of boundary condition viz. Periodic boundary condition and homogenous boundary condition for this case. My doubt is two folds:
1) What is the theoretical difference between these two kinds of boundary conditions?
2) how to apply these boundary conditions in a finite element framework, along with loading?. Specifically, I am interested to know what are the boundary condition on the 4 corner nodes of RVE, and how to apply loading?
Thnks in advnce,
Full scholarships available at European Commission funded workshop on physics based material models in Izmir / TurkeySubmitted by Tuncay Yalcinkaya on Wed, 2013-11-13 20:49.
European Commission' s JRC (Joint Research Centre) is organizing the 3rd workshop on physics based material models and experimental observations (http://iwpmeo.org/) in collaboration with University of Oxford, Max-Planck-Institut für Eisenforschung and Middle East Technical University. The workshop will be held in Izmir/Turkey on 2-4 June 2014.
The LEM3 laboratory (UMR 7239) of Arts et Métiers ParisTech, Metz-Lorraine announces 2 postdoc positions and 1 PhD position.
Postdoc position 1
Subject: Influence of microstructural parameters in service performance of automotive components consisting of SMC (Sheet Molding Compound) and SMC hybrid.
It is a project of LEM3 of Arts et Metiers ParisTech Metz, Loraine funded by external collaborator (American Company OWENS CORNING).
Program duration 18 months, initial contract for one year.
Salary: approximately 2000-2200 euros net.
Starting date: ASAP.
Mechanical characterization and micromechanical modeling of bread dough. J.Rheol [http://dx.doi.org/10.1122/1.4768463]Submitted by fendi on Sun, 2013-10-13 23:44.
The mechanical behavior of dough, gluten, and
starch was studied in an effort to investigate whether bread dough can be
treated as a two phase (starch and gluten) composite material. Mechanical
loading tests revealed rate-dependent behavior for both the starch and the
gluten constituents of dough. There is evidence from cryo-scanning electron
microscopy that damage in the form of debonding between starch and gluten
occurs when the sample is stretched. In addition, the Lodge material model was
found to deviate from the tension and shear stress-strain test data by a
Postdoctoral position at IMDEA Materiales (Madrid, Spain) in crystal plasticity finite element simulation of Ni-based superalloySubmitted by jsegurado on Mon, 2013-09-09 09:27.
The research group of Multiscale Materials Modeling at IMDEA Materials Institute seeks a:
Postdoctoral Researcher (PhD in mechanical engineering or materials science)
Postdoctoral Position Available at Masdar Institute in Abu Dhabi: Mechanics of Nanocomposite and Nanostructured MaterialsSubmitted by Rashid K. Abu Al-Rub on Tue, 2013-07-30 08:32.
Determination of the Minimum Scan Size to Obtain Representative Textures by Electron Backscatter DiffractionSubmitted by ystarase on Sat, 2013-06-22 23:09.
Multiple post-doctoral positions in the field of modeling, simulation, assessment and optimization of multi-functional materialsSubmitted by jenda_z on Fri, 2013-05-03 01:26.
The Czech Technical University in Prague - University Center for Energy Efficient Buildings offers nine post-doctoral positions in the field of modeling, simulation, assessment and optimization of multi-functional materials and structures.
Start date: as soon as possible after 21 June 2013, until all positions are filled
Contract duration: until 30 June 2015 (with a critical evaluation after the first year)
The present project integrates nine different topics, each of which will be supervised by a mentor from the Faculty of Civil Engineering of the Czech Technical University in Prague. The particular topics include
The longitudinal compression strength of unidirectional composites F1c, also called Xc, is very difficul to test for, so often you don't have the value for the particular material (fiber, matrix, volume fraction) that you wish to use. Further, just having data does not tell you what paramaters really influence its value--it is not the compressive strength of the fiber, I can assure you. So, there is a simple formula that you can use to predict its value and also to understand what are the parameters that really affect the compression strength of the composite. For that you need to check out this paper: Barbero, E. J. (1998) Prediction of Compression Strength of Unidirectional Polymer Matrix Composites, J. Composite Materials, 32(5), 483-502.
September 4-6, 2013 Frankfurt am Main, Germany
Objectives and topics:
of nanoengineering technologies and creation of nanomaterials opened
new perspectives for a number of areas of industry and everyday life.
These materials demonstrate increased strength, toughness,
biocompatibility, and can ensure higher service properties, reliability
and lifetime of devices and systems.
I am a very beginnerin doing research :-) and my topic is about "micro indentation analysis using continuum dislocation theory". I am applying high-order finite element method for this nonlinear problem.
My plan is first writing a subroutine for the element. However, when I intend to compute the internal force by using Gauss integration, I see a problem with the integrand function of some index of the internal force vector. This integrand is discontinuous function. It is therefore, I cannot get a good approximation with the standard Gauss integration.
I am a beginner in doing research :-) and my topic is about "Micro Indentation Analysis using Continuum Dislocation Theory". I am applying high-order finite element method for this nonlinear problem.
My plan is first writing a subroutine for the element. However, when I intend to compute the internal force by using Gauss Integration, I see a problem with the integrand function of some components of the internal force vector. This integrand is discontious function. It is therefore, I cannot get a good approximation with the standard Gauss integration.
A joint workshop of the ISSMGE TC101-TC105: Experimental
Micromechanics for Geomaterials will be held on 23rd-24th May
2013 at The University of Hong Kong.
Abstracts are now invited, until the 1st October 2012. They should
be 200-300 words in length, written in English, and show relevance
to the theme of the workshop. Abstracts should be sent to Ms Bridget
Lam. Email: firstname.lastname@example.org (subject: EXP MICRO 2013)
See also attached flyer.
One postdoc and several PhD student positions are available at Arizona State University for fall 2012. Research background in at least one of the following areas is preferred.
1. Fatigue and fracture of materials and structures
2. Computational mechanics and micromechanics
3. Damage detection for composite materials
Interested candidates please send application documents to email@example.com
MPI für Eisenforschung, Düsseldorf, Department for Microstructure Physics and Alloy Design
Post-Doc or PhD Position: Characterizing and modeling the mechanics of crystalline interfaces
A solid background in physical metallurgy, polycrystal mechanics,
dislocation plasticity, continuum mechanics and proficiency in English
are required. Prior experience in microstructural characterization such
as EBSD or AFM is beneficial. Programming skills (Fortran, Python,
Matlab) and experience in numerical simulation and finite element
modeling are strongly appreciated.
CADEC is an online application that performs composite materials analysis as described in the textbook Introduction to Composite Materials Design-- Second Edition, CRC, 2010.
This web application implements the equations for:
- Ply Mechanics
- Fabric-Reinforced Composites
- and Beams
I am writing to let you know the release of VAMUCH 3.0, the 3rd version of our general-purpose micromechanics code. The main new features are:
1. Multiphysics capability: VAMUCH can be used to homogenize heterogeneous materials which have coupled or uncoupled responses to mechanical field, electric field, magnetic field, and thermal field. It not only predicts elastic, conductive, dielectric, magnetic, and diffusive properties of heterogeneous materials but also coupled properties such as coefficients of thermal expansion, pyroelectric, pyromagnetic, piezoeletric, piezomagnetic, and/or eletromagnetic properties, as well as the local fields corresponding to these multiphysical responses.
The stability of anisotropic electroactive polymers is investigated. A general criterion for the onset of instabilities under plane-strain conditions is introduced in terms of a sextic polynomial whose coefficients depend on the instantaneous electroelastic moduli. In a way of an example, the stable domains of layered neo-Hookean dielectrics are determined. It is found that depending on the direction of the electrostatic excitation field relative to the lamination direction, the critical stretch ratios at which instabilities may occur can be either larger or smaller than the ones for the purely mechanical case.
2 Year PDRA Opportunity in:
Image Based Modelling to Improve Damage/Fracture Tolerance in Materials
Postdoctoral Positions at the University of Pittsburgh in Cellular Mechanics and Biophysics of Morphogenesis
Postdoctoral Positions are available for highly qualified and motivated candidates to study the physical principles of morphogenesis in the Davidson Laboratory at the University of Pittsburgh in the Department of Bioengineering. The laboratory focuses on studying the molecular-, cellular, and tissue-scale processes that regulate mechanical properties and force-production during morphogenesis. Projects involve a combination of biophysics, cell biology, bioengineering, and embryology.
Two post-doctoral positions are available immediately at the Univeristy of New Brunswick, Fredericton, Canada. One is in the area of micromechanics of deformation and fracture of engineering materials, particularly metals; and the other is in composite material modelling. For the former position, experience in microstructure-based modelling of deformation and fracture of metal alloys is preferred; while for the latter one, multiscale finite element modelling of fracture and damage behaviour of composite materials is required. Proficiency in commercial finite element codes, such as ABAQUS, ANSYS, or LS-DYNA is a must.
Interest applicants please contact Dr. Zengtao Chen at firstname.lastname@example.org for more information.
I'd like to discuss here my result about residual stress. I calculated with Abaqus a thermal transient from 20 to 300°C +relaxation(unconstrained, keeping the same final T=300°C) on a planar model of a composite material (simplified). The 2 circles are tungsten (W), the Matrix is copper (Cu). Stress (eigenspannung) should arise from mismatch of expansion coeffiecients (CTE_W~0.3*CTE_Cu), but it should also desappear after relaxation, since circles and matrix are free to expand and both modeled as pure elastic phases. Despite the model is perfect elastic and free to expand in x and y (only BOTTOM nodes are fixed in y), I get non-zero stress across the region.