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 research laboratory for Quantitative Acoustic Microscopy and High
frequency spectroscopy of the Julius Wolff Institute &
Berlin-Brandenburg Graduate School for Regenerative Therapies, Campus
Virchow-Klinikum - Prof. Dr. Kay Raum – is opening the two Doctoral
Researcher (PhD) positions immediately.

We are looking for two motivated graduate students with excellent
academic performance and interest in conducting interdisciplinary
research.

Position I
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Position ID: DM.138.11

Project description

Dear Colleagues,

I wish to bring to your attention my recent work with Liping Liu on "A homogenization analysis of the field theoretic approach to the quasi-continuum method" to appear in the Journal of the Mechanics and Physics of Solids. Below is the abstract and attached is the preprint of the article. I will very much appreciate your comments and suggestions.

A Homogenization Analysis of the Field Theoretic Approach to the Quasi-Continuum Method

There is a lot of homogenization theories based on penetrable model or some other name like 'overlapping', 'randomly imbedded model' to analyze random microstructure. In reality, the fibers or inclusions can not be penetrated into each other, so why they use this assumption anyway?

 Thanks for your opinion.

This is a general micromechanic question.

Hello Everybody,

I have some problem, i use 3D unit cell model for the calculation of stress-strain curve of the soft plastic matrix with rigid inclusion. after calculation i take the reaction force, devived it into cross -section of ma specimen=this is my stress, and strain i obtain by deviding the displacement into he initial length of the specimen. nevwrtheless i think it is necessary to use some homogenization scheme to obtain the stress-strain response of the material. Could you please help me what should i do?

Best regards

ABAgirl

A fully funded PhD position is immediately available in the area of multi-scale modeling of geomaterials within the research project "Failure of cohesive geomaterials: bridging the scales - GEOBRIDGE" at Laboratoire Sols, Solides, Structures - Risques (3S-R), Université Joseph Fourier, Grenoble, France.

Hello All. This is my first blog entry in iMechanica!. This post is about my new paper with Prof. Amine Benzerga entitled "A constitutive model for plastically anisotropic solids with non-spherical voids", accepted for publication in JMPS (URL: http://dx.doi.org/10.1016/j.jmps.2010.03.007 ). In case you are not able to view the online version, a preprint of the paper is attached. This paper should be of interest to anyone working in the ductile fracture area. Your comments and feedback are welcome.

A fully funded PhD position is available in the area of multi-scale modeling of geomaterials within the research project Failure of cohesive geomaterials: bridging the scales - GEOBRIDGE at Laboratoire Sols, Solides, Structures – Risques (3S-R), Université Joseph Fourier, Grenoble, France. 

Dear All,

Could somebody indicate me some literature about the topic "2D
approximation of heterogeneous 3D media"?

In particular I am interested to address following issues:

1) Under which conditions averaging thermal conductivity and young
modulus (or more general, mechanical behaviour) on multiple 2D crossections of an heterogeneous "random"
material can be a good approximation for the behaviour of the real 3D
microstructure

2) Is there any  theorem which shows the equivalence between averaging
on n 2D crossections of a certain media and taking the single
real 3D structure for n sufficiently large?

Thank you very much in advance.

Phu

Concrete is currently the most important material in the building industry. However, it is very weak in tension,  compared to its strength in compression. To overcome this problem, prestressed concrete is usually used.  Prestressed concrete is plain concrete with reinforcement of steel, polymers or, in this case, shape memory alloys. The prestressing is usually introduced by applying tension to the reinforcement in the concrete members. Consequently, initial compressive stresses are transmitted to the concrete matrix; the application of permanent  compressive stress increases the apparent tensile strength of the concrete, since upon tensile loading, the compressive stresses must first be nullified.

In a piezoelectric material an applied uniform strain can induce an electric polarization (or vice-versa). Crystallographic considerations restrict this technologically important property to non-centrosymmetric systems. It can be shown both mathematically and physically, that a non-uniform strain can potentially break the inversion symmetry and induce polarization even in non-piezoelectric dielectrics. The key concept is that all dielectrics (including non-piezoelectric ones) exhibit the aforementioned coupling between strain gradient and polarization-an experimentally verified phenomenon known in some circles as the flexoelectric effect.