research

Babichev's picture

Abaqus remesh technique

Hi, folks! I'm a new user of Abaqus. Please can you help me with remesh, ALE remesh technique in Abaqus/CAE. May be you have any example in Abaqus/CAE. If you have any, plese me on babichev@uiggm.nsc.ru.

Thanks! 


CURVED HOLLOW BEAMS

HELLO EVERYONE:

 

FIRST TIME EVER ON THIS SITE, IT IS GREAT!

WELL, IF YOU HAVE QUESTIONS TO ASK JUST SHOOT, I AM BEGGINING AN SPECIALIZATION IN STRENGHT OF MATERIALS AND I MAY KNOW SOME THINGS.

AS PER ME, I HAVE A QUESTION. I AM WORKING ON CURVED BEAMS AND I HAVE A HOLLOW SECTION THAT GENERATES DOUBTS IN ME; I HAVE APPLIED WINKLER SINCE I KNOW IT WILL WORK WELL TAKING INTO ACCOUNT THE THICKNESS OF THE WALLS AND CALCULATING SOME COEFFICIENTS FROM OLD BOOKS OF TIMOSHENKO (THAT SOMEWAY TOLD ME TO APPLY WINKLER, BUT...), SO I WOULD LIKE TO KNOW IF YOU HAVE STUDIED SIMILAR CASES AND THE WAY YOU SOLVE IT.


Jie Wang's picture

Domain control in ferroelectric nanodots through surface charges

The ability to control the domain patterns in ferroelectric nanostructures holds promise as a method to tailor physical properties for specific applications. We proposed a new way to control the domain patterns in ferroelectric nanostructures. Desirable domain patterns can be obtained through different surface charges. The surface charges can be supplied by the atomic and molecular adsorbates on the surfaces of ferroelectric nanostructures.


John E. Dolbow's picture

Deadline Extended for 21st Annual Melosh Competition

The deadline for abstracts for the 21st Annual Melosh Competition has been extended until January 30.  All interested graduate students are encouraged to apply.

 This competition for the Best Student Paper in Finite Element Analysis will be held at Duke University on Friday, April 24, 2009.  The competition has become one of the premier graduate student events in the broad area of computational mechanics.  


modeling of simple beam-column connection (hinged)

Hi, I am using Abaqus.

Need to model simple beam-column connection (with beam elements). Connection should allow rotation but not translation. I am new to Abaqus so please help.

 

Tried connector section, defined it, but I dont know how to use/apply it.


Advantages of XFEM over std FEM

Hi all .. What are the advantages of XFEM over std FEM other than remeshing ? 

Because when ever  XFEM is introduced only remeshing alone is highlighted ... Can the experts from this field please list out the other advantages?

 
All above are in context to Fracture.

thanks in advance. 


Tecplot 360

I am creating a mesh for a composite material using Fortran by assigning two different material markers for the data. I am able to see the output in tecplot but i would like to set two different colors for the two materials such that i can see the same in tecplot. As of now, i can see just one color for the whole mesh and i cant differentiate where the second material is distributed. Please suggest on how i can see the tecplot with different colors for the two different materials i have used in my .dat file. I am new into using all this so i need the advise. please suggest.


clauvelin's picture

Plectonemic DNA Mechanics

a recent pre-print about the mechanics of plectonemic DNA in extension-rotation experiments (under submission Biophysical Journal)

http://arxiv.org/abs/0811.1840

Journal version: http://www.cell.com/biophysj/abstract/S0006-3495(09)00564-5

Authors: N. Clauvelin, B. Audoly,  S. Neukirch


modeling of Porous medium and its solution methods in ABAQUS?

Hi all,

I am krishna working on FE knee joint modeling in ABAQUS. I am beginner to Abaqus
As i have read from the journal papers, I understood that cartilage and meniscus are poroelastic (porous medium).

My axisymmetric model consists of following.
1. Cartilage is modelled with CAX4PH (axisymmetric pore pressure elements)
2. Meniscus is also with the same elements
3.Tibial bone with CAX4 elements.

Since
contact beween two deformable bodies create computational difficulties,
I am using membrane with low stiffness between the cartilage and
meniscus.

Membrane is tied to meniscus and modeled with MAX1 elements.


clauvelin's picture

Elasticity of Knots

a recent pre-print concerning the elasticity of a knotted rod (submitted to Journal of the Mechanics and Physics of Solids)

http://arxiv.org/abs/0812.2881

Authors:  N. Clauvelin, B. Audoly, S. Neukirch


How to calculate varying moment of inertia in a slender beam given final curve of deflection?

I have no mechanics background so be gentle. Looking for advice on how to approach this problem:

I have a long, slender, straight beam that is then bent into a curve using wire rope as a tension element between either end. Very similar to an archery bow.

I want the final shape of the beam (specifically the surface away from the radius of curvature) to be a parabola whose vertex is in the center of the beam. The beam will be a constant thickness but varying width. Modulus of Elastisity is assumed constant and there is no yielding in the material (or a thickness that prevents the stress from rising too high is selected).

By varying the width and therefore the moment of inertia, I should be able to follow the parabola.  


Calling UMAT in abaqus

 Hello,

 I am trying to figure out how to call UMAT through the abaqus command. I have a local abaqus licence. How do I get into the command window to type in the commands? I have installed fortran. I am trying to run one of the examples in the manual which gives me the .inp file and .f file. I went through a number of forums and the manual which tells me to use compile_fortran and abaqus make commands. Can someone guide me through the procedure? I am using version 6.7-5.

 

Thank you 


How to perform post-buckling analysis using ABAQUS correctly?

Hi all,

How to perform post-buckling analysis using ABAQUS correctly?

I have obtained an eigenvalue from a linear analysis using BUCKLE command. The shape from mode 1 is good (tally with the physical experiment).

However, the result from the post-buckling analysis (using IMPERFECTION command and RIKS analysis) has not produced the buckling shape like the mode 1 from the linear analysis.

If you all have any suggestion, please share it with me. Greatly need it.

Thanks,

Wanbot 

 

 


Constitutive Matrix for Viscoelasticity

Hi,

 

Can anyone please tell me the constitutive or the 'C' matrix  for a linear viscoelastic material model (with no relaxation in bulk)? I have been using the one outlined in the Computaional Mechanics book by Simo and Taylor, but I feel that ANSYS is using a different matrix as my results are different from ANSYS. I could not find details about the 'C' matrix for a viscoelastic material anywhere else. Any links too might be helpful.

 

Thanks,

Shriram

 --------------------------------------

Research Assistant

Structural and Multidisciplinary Optimization Lab.

University of Florida


ruogang zhao's picture

Comments to this month's journal club

Don't know why the post to the journal club won't show up, post it here instead.

In addition to the tissue engineering application, the study on cell mechanics is also motivated by the interest on the mechanotransduction – the process of converting physical forces into biochemical signals and integrating these signals into the cellular responses. I’d like to add this perspective to the discussion. Understanding the mechanotransduction requires the integration of the measured mechanical properties (stiffness, viscoelastic time constants, etc) and the cell biology; thus, it poses a main challenge to the cell mechanics. 


shaochj's picture

Look for a postdoc or research position in structural engineering

My research interest focuses on concrete damage constutitive model and its numerical implementation, performance-based seismic design of bridge structures, variational integrand method and conservative propertied of irreversible process, methmatical base of damage theory .Now I work as a postdoctoral research till Sep. 2009 at Tongji University, P R China.  My current research are supported partly by China Postdoc Fund Committee and Shanghai Postdoc Fund Committee.


defining a node and element locations while meshing a volume

Hi,

 

     I am trying to model a piezo disc bonded to a steel plate for lamb wave simulation. I am currently modeling the piezos as rectangular with nodes coincident with the plate nodes and just coupling them. I would like to do that with a circular geometry for the piezos, but for that I need to define nodes in the disc that coincide with the plate nodes. How can I do that? Can I define my own node locations in a volume for meshing? Thanks in advance for your help.

 

Muhammad Haroon


Teik-Cheng Lim's picture

International Journal of Novel Materials

A new journal in Materials Engineering, with emphasis on mechanical properties, will be launched this year.

 

The home page is at:

 http://www.serialspublications.com/journals1.asp?jid=438

 Author instruction can be found at:

http://www.serialspublications.com/journals1.asp?jid=438&dtype=1&jtype=

Online submission at:

http://www.serialspublications.com/journal_form.asp?jid=438&jtype=

 


MDS of CNT

Can anybody tell me what is the most suitable software for molecular dynamic simulation of CNT from SIESTA and Material Studio?


About: why we have not synthetic diamonds

 

 

                              About: why we have not synthetic diamonds.


Journal Club Theme of January 2009: Impetus for Cell Mechanics

Welcome to the January 2009 issue. This issue addresses the important discussion on cell mechanics. Acute need to study cell mechanics is driven by the fundamental goal of tissue engineering i.e. to make tissue engineered constructs that can mimic the environment for tissue regeneration with a potential to replace the biological functions of damaged organs. There is now worldwide activity in the in vitro regeneration of tissues including nerve, liver, bone, heart valves, blood vessels, and kidney.


Shailendra's picture

Post-doctoral postion in Mechanical Engineering at NUS

I have an opening for a post-doctoral position starting early next year (Jan 2009) in the broad area of multi-scale mechanics of nano-crystalline (nc) materials. The focus will be on microstructure mediated failure processes in nc materials primarily using continuum mechanics based approaches, but informed by materials science.

If you are interested, please send me (shailendra[at]nus[dot]edu[dot]sg) your CV and the names of at least two references.

Thanks,

~Shailendra


Modeling anisotropic hyperelastic material

Recently I work on Finite Element Modeling of human eye .  And focus on cornea .( the outer transparent layer of human eye) . Based on Its structure which consist of collagen fibers I have to use the Anisotopic hyperelastic model . And I derived the coefficients of
strain energy function which divided into three terms of :  volumetric,isotropic and anisotropic

But I have some troubles to modeling this material in Ansys v.10 Beacause I have to use UMAT subroutine and I have not enough information about how to define material with macro in Ansys.  So would you mind introduce me usefull links about predefined UMAT in Ansys


Lee Margetts's picture

DHPA Dinosaur Fellowship

Please note that the DHPA award is no longer available. We look forward to Ms Zartasha Mustansar joining us in January 2009.


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