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Opening for a Post-Doc position: Adaptive anisotropic mesh for automated geometric reconstruction

A postdoctoral researcher is required to work on adaptive
anisotropic mesh refinement algorithms for the CEMEF, Center for Material
Forming at MINES ParisTech in Sophia Antipolis, French Riviera, France.

Zhigang Suo's picture

Interfacial Fracture

These notes belong to a course on fracture mechanics

A body consists of two materials bonded at an interface. On the interface there is a crack. The body is subject to a load, causing the two faces of the crack to open and slide relative to each other. When the load reaches a critical level, the crack either extends along the interface, or kinks out of the interface.

Emden-Fowler Differential Equation

I input into MAPLE the following differential eq & it returned that it is classified as an Emden-Fowler Differential Equation:

r^2*F"+1/r*F'-k^2*F=0   where F is a function of r

MAPLE was able to generate a solution.  I am attempting to figure out how this eq is actually solved & I typed in Emden-Fowler into the SEARCH window on this website & got ZERO results.

Tire-Water-Pavement contact problem

Hello all,

I want to model hydroplaning problem in abaqus. how to simulate water component in between tire and a pavement in abaqus.

I want to use either Coupled-Eulerian-Lagrangian algorithm or Aribitrary-Lagrangian-Eulerian algorithm at the contact patch but i could find any one of these features in abaqus.

Please tell me in detail, if any one has done this problem in abaqus.

Thanks a lot





Which program? ABAQUS, Comsol or Ansys

Hi all,

I am a PhD student at the first months. I have to choose a finite element software to study impact effect on biological soft tissues. After some web researches the softwares which seem to be more suitable are ABAQUS, Comsol Multiphisics and Ansys.
My intention is to develop an user defined material model considering the material as anisotropic porous-visco-elastic.
I would appreciate some suggestions/opinion. I am specially interested in dynamical simulations.

Stress triangular mesh

Hi all,

I have some
problems with understanding correctly the stress (e.g. Cauchy stress)
calculated by Abaqus. The boundary value problem consists of a square
where the top side is displaced up by 20% of its original height while
the bottom side is fixed. Now when I use a quadrilateral mesh the
result is clear. But what happens when a triangular mesh is used? Why
some triangles have a negative stress? In the figures the S11
component of the Cauchy stress tensor is plotted.

Physical significance of higher order spatial derivatives of displacement (longitudnal loading)


I have encountered fourth order space derivative in the PDE derived for
smart material.I am looking for the physical significance of higher
order spatial derivative of displacment in longitudnal loading. In the
Euler-Bernoulli beam theory (lateral loading), the fourth order space
derivative referes to the load. 

In longitudinal loading, the first order space derivative is strain i.e 
du/dx .What are the significane of higher order space derivatives d^2
u/dx^2 , d^3 u/dx^3 , d^4 u/dx^4?

Please share your expertise.

stress - Strain diagram

hi all,

Why the stress values are on Y-axis and strain values on X-axis?

If we interchange the stress on X axis and strain on Y axis , will there be any change or is it possible to change?





FEM for thermoelectric effect (seebeck, peltier, thompson effect)

Hi, I am looking for an opensource FEM tool to solve thermoelectric problems which involve seebeck and peltier effect. Any suggestion?

boundary element metod software question

Choose a channel featured in the header of iMechanica: 


I have written the program in C++ which is based on one of BEM (Method
of fictitious loadings) . I know there are a lot of open libraries of
functions for programming for example openCV or OpenFEM. I could not
find Open Source library for BEM. Please if you know them, give links.

Thanks and Regards,



jenda_z's picture

Localization of Inelastic Deformation 2010

Dear colleagues,

I would like to bring to your attention the advanced course on Modeling of localized inelastic deformation that will be taught by Milan Jirasek in Prague, Czech Republic on 13-17 September 2010. 
More detailed information on the course is posted at We are looking forward to seeing you in Prague!

Wrong pore pressure and effective stress state in ABAQUS


I want to model an anchored sheet pile wall placed in a completly saturated clay material, where
the excavation steps on the left side of the wall have to be taken into account.

I am using the keyword in ABAQUS "*Model change, Remove" to remove my elements, so I can
simulate the excavation steps. Unfortunately, my pore pressures seem stranges in the
model when I am using this keyword.

Postdoctoral Position in Computational Mechanics

The University of New Mexico, Department of Mathematics and Statistics, and/or the Department of Mechanical Engineering, is seeking candidates for a post-doctoral position to conduct research in the area of computational geomechanics for a project related to modeling the effect of rock joints on tunnel failure. A start date about June 1, 2010 is anticipated, subject to final budgetary approval. A Ph.D.

question about explicit integration

Choose a channel featured in the header of iMechanica: 

Hi everyone,

Oden Warren's picture

Nanomechanics symposium at SES 2010

Dear Colleague: Please consider submitting your nanomechanics related abstract to Symposium 4-1 ("Nanomechanics: Beyond Modulus and Hardness") of the 47th Annual Technical Meeting of Society of Engineering Science, which takes place October 4-6, 2010 at Iowa State University, Ames, IA. The deadline for abstract submission is 5:00pm CST, Monday, June 7, 2010. The meeting's homepage can be found at

Research Position Opening on Energy Harvesting

Applicants are invited for an immediate opening of a postdoctoral
researcher position at Northwestern University. This researcher will work on
a research project on vibration energy harvesting that involves close
collaborations with experimentalist. Candidates should possess an earned
Ph.D. in Mechanical Engineering, Physical sciences, Electrical Engineering,

Twebb83's picture

Free Webinar - April 27 - Evolve Linear Dynamics Methods with Abaqus FEA

Register to attend this free webinar:
Tuesday, April 27 - 11 a.m - 12 p.m. EDT

Learn how to evolve linear dynamics methods using the accurate, realistic
simulation technology of Abaqus FEA.

>> Register today for this free webinar

Bo Li's picture

Dielectric strength: dependent or independent of stretch?

 Dielectric elastomer can undergo giant deformation, but are susceptive to various failure modes. i.e electrical breakdown.

Some experimental papers (Kofod, Plante, Chen, see the attachment) reported the dielectric strength of VHB material (a kind of dielectric elastomer) under difference pre-stretch, equal bi-axially or unequal bi-axially. And the strength (maximum voltage can be applied before breakdown) has be greatly improved by these mechanical stretches.

 So here comes the question: is the dielectric strength dependent or independent of stretch?

Twebb83's picture

Coconuts, Blood Cells, Snail Armor - What do they have in common?

As the 2010 SIMULIA Customer Conference approaches, it reminds me of a thought-provoking presentation given by Dale Berry of SIMULIA at the 2009 SCC in London.

He reminded the audience, of engineers and researchers, that Realistic Simulation is not only good for evaluating mechanical behavior of product performance, but it’s also an indespenible tool for driving innovative research that improves our lives and society.

Zhigang Suo's picture

Mixed-Mode Fracture. Curved Crack Path

These notes belong to a course on fracture mechanics

A crack pre-exists in a body. When the body is loaded, the two faces of the crack may simultaneously open and slide relative to each other. The crack is said to be under a mixed-mode condition. When the load reaches a critical level, the crack starts to grow, and usually kinks into a new direction. Subsequently the crack often grows along a curved path.


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