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Nonlinear Dashpot

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How to simulate a nonlinear dashpot in Abaqus

Jianliang Xiao's picture

van der Waals interaction controls orientations of single-walled carbon nanotubes on quartz during growth

Single-walled carbon nanotubes (SWNTs) possess extraordinary electrical and mechanical properties, with many possible applications in electronics and materials science. Dense, horizonally aligned arrays of linearly configured SWNTs represent perhaps the most attractive and scalable way to implement this class of nanomaterial in practical systems. Recent work shows that templated growth of tubes on certain crystalline substrates (e.g. quartz) yields arrays with the necessary levels of perfection, as demonstrated by the formation of devices and full systems on quartz.

Material modlelling


Any body working on microstructural modelling, here i want know how to construct Basic real microstructure to FE mesh ?? 

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

UDEC Itasca


 I would like to ask if anyone knows how to calculate the length of open joints with UDEC? Any help is wellcome!

Thank you


Vasilis Sarhosis

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.

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  ???

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.


Communication between Matlab and Nastran

Hi All,

 Could you please tell me how I can make communication between Matlab and Nastran? Actually I want to send some force data from Simulink to a deformable object in Nastran and then I will read the deformation of the object in Simulink. After that I will recalculate the forces and send it back to Nastran till some desired criteria is made. Can anybody help me to figure out this? Could you please pass it to me if you have any source code?

Thanks in advance


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.  

salem's picture

Microelectronic Engineer

My research based on the application of piezoelectric materials for power harvesting aspects by using ANSYS simulations in MEMS area. 

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.

mohamedlamine's picture

Mechanical Vibrations of the Gear Teeth

Recent research work available on request.


Cohesive material zone model and ABAQUS subroutines


I'd like to ask if anybody knows if it is possible to use an ABAQUS usersubroutine that could vary some parameters (τmax, kn or ks etc) of the cohesive zone model of ABAQUS with the vertical pressure applied on the interface. The new ability of ABAQUS to support cohesive behaviour in contact surfaces seems very interesting and useful, however how could somebody simulate the interface under a compression - shear regime that may follow a Mohr-Coulomb type behaviour?

Jianliang Xiao's picture

In-surface Buckling of Silicon Nanowires on Elastomeric Substrates

Buckling of thin layers or aligned arrays of stiff materials on elastomeric substrates has many important applications, such as stretchable electronics, precision metrology and flexible optoelectronics.  These systems show one common phenomenon, the stiff thin layers buckle normal to the substrate surface (out-of-surface buckling).  By contrast, we recently reported for the first time that silicon nanowires (SiNWs) on elastomeric substrates buckle only within the substrate surface, i.e. in-surface buckling.


How do i find the bearing stifness of a ball bearing, theoriticaly

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How do i find the bearing stifness of a ball bearing, theoriticaly.. is there any advanced software for finding bearing stiffness

Aerodynamics of Flapping Wings for Biomimetic Flying Devices

We present an interesting application of ADINA FSI in the
analysis of biomimetic flying devices. Please see

You can find many other examples of applications of ADINA in the
analysis of multiphysics problems here:

[Newton-Raphson Iteration in Transient Thermal Analysis

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I have been quite confused about this for sometime now. It
has not been mentioned clearly in the books/references that I have
looked into.

In transient thermal analysis with implicit scheme
or the Crank Nicolson scheme, are there Newton Raphson iterations based
on the residual vector in every time-step?

Process Engineer
Moore Nanotechnology Systems
Keene, NH - 03431

Topology optimization

Dear members,


I need some suggestions about review articles on "Topology optimization of inelastic materials". If some one have it please forward it to me.


Thanks in advance.

Damage modeling in ABAQUS 6.9 in surface based cohesive behavior

I am working on shear failure of sandwich composites.I have modelled a sandwich composite with surface based cohesive behavior in ABAQUS 6.9.Now i have to do damage modelling.

razi's picture

My initial experience with VTK

I wrote my first experience of using VTK with my hp-FEM code here.  This is only with linear tetrahedra. To use VTK for high-order elements seem formidable, altough there's a paper that describes how it can be done. If anyone has experiences with VTK in FEM, I'd love to consult with you. 




My Name is Moiz. I need some material about composite parts fabrication and the details about how the ply geometry is decided based on strength requirements. Any help would be really appreciated.



Zhigang Suo's picture

Dielectric elastomers of interpenetrating networks

Recent experiments have shown that a voltage can induce a large deformation in an elastomer of interpenetrating networks. We describe a model of interpenetrating networks of long and short chains. As the voltage ramps up, the elastomer may undergo a snap-through instability. The network with long chains fills the space and keeps elastomer compliant at small to modest deformation. The network with short chains acts as a safety net that restrains the elastomer from thinning down excessively, averting electrical breakdown.  It appears possible to find a dielectric elastomer capable of giant deformation of actuation.  You can read the paper, or take a look at the slides posted here.

SivaSrinivasKolukula's picture

Eartquake analysis

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    When I was going through few research articles related to earthquake analysis, they say: A compuetr code was developed where in which the eartquake input will be in either accelerogram or a displacement time history, digitized in in the appropriate format. What does it mean? Doest it mean that in studying simulation of seismic analysis  we need to load that code as input? How to get an idea about that codes? Where to get? How to use?

   Please help.........

Thanks in advance........


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