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Melosh Competition: 2nd Call for Abstracts and Travel Fellowships

This is the second call for abstracts for the 22nd Annual Melosh Competition for the Best Student Paper on Finite Element Analysis.  Extended abstracts are due by January 8, 2010.   Details of the competition and submission procedure can be found here

BoJing Zhu's picture

Can we use constitutive relation at micro/macro scale to molecules scale ?

Hi, everyone


Now I meet a problem, wish can obtain you help.


Now i do some research on multi-compose particle materials (eg. pharmaceutical science  materials)___predict the compressibility, compactibility, flow properties and  breakage behavior.

as we know, the molecular scale at 0.1-70nm scale and crystal growth process at 0.1-100nm scale, can i use the constitutive relationship at micro(=~um)/macro to analyze the performance and structure at this scale.


thanks ! 

Amit Pandey's picture

2009 Nathan M. Newmark Medal

C. S. Desai Is Recipient of the 2009 Nathan M. Newmark Medal

C S Desai

Regents’ Professor Chandra Desai has been awarded the 2009 Nathan M.
Newmark Medal by the Structural Engineering and Engineering Mechanics
Institutes of the American Society of Civil Engineers.



Hi all,

 I´m traying to simulate a low-cycle fatigue crack growth in Abaqus 6.9 using xfem. My problem is to add the low cycle method to the xfem solution. 

I believe that the only current option for this would be to manually
create the loading curve and to do the analysis by a brute force
method but i may not be correct in this assumption however.

Please could someone explain a brief method.

i appreciate in advance.



Buryachenko's picture

Welcome to new background of micromechanics

Dear Colleagues,

 I am please to let you know about the birth of a new background of micromechanics defining a new field of micromechanics called computational analytical micromechanics (CAM). It offers opportunities for a fundamental jump in multiscale research (see the abstract attached, where avalable electronic publications are indicated and encouraged for reading). However, these opportunities can be realized only in the case of joint efforts of both computational micromechanic's society and the analyticalone. I would be happy if CAM piques your attention.

GOPALAERO2000's picture

Residual stress measurement

Hi Everyone,

 I would like to measure the residual stress imposed pattern through thickness of the plate by forming process (bending). Is it possible?

 I came to know that residual stress measurement through HOLE DRILLING METHOD offers only on the surface. That too, applicable only when residual stress imposed is uniform through thickness (like shot blasting process). If any one came across the experience of residual stress measurement, please throw some light in this regard.

 Thanks in advance

 M Gopalakrishnan

Post Doctoral Research Associate in the area of high strain rate loading and multiscale modeling at RPI

There is an immediate opening for a postdoctoral research position in the Advanced Computational Research Laboratory at RPI, Troy NY to work on problems involving high strain rate loading conditions and multiscale modeling. Encouraged to apply are creative, self-motivated candidates with a sound background in computational mechanics. RPI is home to the CCNI, one of the most powerful university-based super-computational research facilities in the world.

rajnish0007's picture

How to simulate pull out test in ABAQUS ??

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hello all

How to simulate pull out test in ABAQUS 6.9  ???

How to deal with negetive plastic strain increment in FEA in an elasto - plastic problem

In case of elasto-plastic problem it is mentioned that unloading of an integration point should be started along the elastic moduli when the solution gives a negetive increment of the plastic strain at the integration point. If anyone could elaborate it a little more, it will be really helpful.


asit_rathod1's picture

Stress Defination

Hello All//

I am always confuing on that Stress is a point Function..and not Seen Physically Than Stress is a material Property or Material Behaviour?

Waiting For Answer..


Wendtland (1972) experimental results on natural frequencies of cracked cantilever beams

The effects of edge cracks on the natural frequencies of cracked cantilever beams have been extensively studied by Wendtland (1972). These results are referred to by quite a number of related journal papers; the refernce is:

Wendtland D. A¨ nderung der biegeegenfrequenzen einer idealisierten Schaufel durch Risse. Ph.D. Dissertation, University of Karlsruhe; 1972.

Does anyone know how this can be accessed online, or atleast the complete set of results for eigenfrequency (first three modes of vibration) changes due to edge cracks at different positions and depths?

Post Doc position available in hybrid design of armor panels (with ceramics, composites) @ NTU, singapore

There is a Post doctoral Position available with my supervisor Prof.Sridhar Idapalapati.  The candidate should have PhD degree with background in  impact mechanics, fracture mechanics and exposure to finite element modeling packages such as AUTODYN software. Exposure (handson) to drop tests or Hopkinson bar tests is an added advantage.

If u are interested plz contact him directly @


A basic question

Hello Everyone,


Could you address me to a comprehensive description for relationship between fatigue and fracture  in prediction life Fatigue crack growth life?


i appreciate in advance,


Tim Rupert's picture

Experimental Observations of Stress-Driven Grain Boundary Migration

My coworkers (Dan Gianola, Yixiang Gan, and Kevin Hemker) and I have published research results in the December 18th, 2009 issue of Science.  In this work, we perform tension tests on specially designed thin film samples to studying the influence of different stress and strain states on mechanically-induced grain growth in nanocrystalline aluminum.  Our results indicate that shear stresses drive grain boundaries to move in a manner consistent with recent molecular dynamics simulations and theoretical predictions of coupled grain boundary migration.


Li Han's picture

New methods of analyzing indentation experiments on very thin films

Abstract - Indentation experiments on very thin films are analyzed by employing a rigorous solution to model elastic substrate effects. Two cases are discussed: elastic indentations where film and substrate are anisotropic, and elasto-plastic indentations where significant material pile-up occurs. We demonstrate that the elastic modulus of a thin film can be accurately measured in both cases, even if there is significant elastic mismatch between film and substrate. 

This manuscript has been accepted for publication in Journal of Materials Research.  

Help regarding Tutorials on Creep using Abaqus

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My research area is modeling of creep in MMC. I am trying to use Abaqus for this purpose but I am unable to find any tutorial that can provide me some help that how to use creep module provided in Abaqus. Will any body can help me by providing some tutorial related to that topic. It will be highly apprecioated.



Elasticity, 3rd edition, J.R.Barber

Springer has just published the third edition of my book

Mario Juha's picture

Consistent linearized tangent moduli for hyperelastic materials... is it always a positive definite matrix?

In order to obtain numerical solution of problemsthat involves a hyperelastic material model, we use what is known as incremental/iterative solution techniques of Newthon's type. The basic idea is to contruct a discrete system of nonlinear equation, KU=F, and solving it using a Newton's method or a modified version of it. As we know, its lead to a systematic linearization of the internal force vector and by the chain rule to the linearization of the material model.

Picking a node within a 3D Solid Volume

hi all,

I have a solid 3D part made of concrete. I would need
the results of a few points inside the concrete. However, I realised it
was not easy to pick them when doing a Set because the nodes are hidden
(they are not on the surface. I have 1) partition my model exactly at
the points when I need to pick 2) i name the points as datum points.

Using the CAE interface, how can i pick this nodes? I have attached a pic for better understanding. Can anyone please advise?

Thank you.

Project Tuva (Feynman's lecture series)

Here is an interesting link I came across while searching for the Feynman lectures -- Project Tuva.

It provides each of Prof. Feynman's seven lectures delivered at Cornell as a part of the Messenger lecture series. This format of posting lectures by Microsoft is absolutely amazing. I hope more such lectures especially videos of keynote lectures in leading conferences and congresses can be made available online.


modelling cyclic plasticity in abaqus


I have to model cyclic plasticity in ABAQUS. The method to use ( this is as per ASME Boiler and Pressure Vessel code) involves only a single loading ( rather the load range has o be applied) and using a stabilized cyclic stress strain data expresssed in Ramberg Osgood format. The parameters for Ramberg Osgood are specified in the equation to be used fpr stabilized cyclic stress strain curve.

 Implementing the same in ABAQUS, gives me the following possibilities :


1) Hardening type Isotropic-which I believe should not be used with cyclic loading.

Problem with fortran code for solving large strain 2D elastic problem by FEM using Updated Lagrangian Framework

I am using my own fortran code to solve a large strain 2D elastic problem using FEM in Updated Lagrangian framework and I am using incremental formulation. It works well for 2D pull of a square block with 2 elements and I've compared the results with a commercial FEA package. But while solving bending of a cantilever beam the results starts to blow up and the elements distort abruptly after certain time step. This happens only when the load or the displacement given at the free end of the beam is large otherwise it works fine.


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