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Periodic Boundary Conditions and Contact Elements with Cohesive Zone Law in Ansys

Mon, 2011-12-12 12:27 - Andreas.Ferber
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contact
periodic boundary conditions
cohesive zone

Hi all,

 

I have a problem with periodic boundary conditions using contact elements with a cohesive zone law in Ansys.

In my micromechanical simulations of an RVE with periodic boundary conditions I would like to have a predefined fracture path. My aim is to realize the fracture path with voronoi cells. There I get problems at the boundary of the periodic domain.

A picture of the simplified problem is attached here:

http://dl.dropbox.com/u/4920002/PBC_CZM.png

 

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Problems with 3D contact/contact status

Tue, 2011-11-15 03:22 - Andreas.Ferber
Forums: 
Contact Mechanics Forum
Free Tags: 
cohesive zone model
contact
Contact Status

hi all,

I have some problems with contact elements in ANSYS.

My model is a cube of matrx containing two fibres with periodic boundary conditions. The interface between Matrix and Fibre is modeled with contact elements and cohesive zone law. 

In 2-D everything works out just fine when bringing up displacement in x-direction. Here is a movie I made of the Contact Status over the loadsteps:

http://dl.dropbox.com/u/4920002/2D_contactmovie_ContaStat_0.4.avi

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suitable contact for sph in LS-DYNA

Fri, 2011-10-14 04:18 - rozaiman
software
contact
SPH

Hi there,

I'm using SPH in LS-DYNA as my tool to simulate the projectile penetrate the box. Both projectile and box are modeled as sph. 

I'm having problem to determine the suitable contact of these two entity.

Could someone please help me... any tips that will help me to tackle this problem is highly appreciated!

 

Thanks... 

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Help in ABAQUS

Sat, 2011-08-20 06:22 - drmaity
research
ABAQUS
contact
Coefficient of Friction
temperature-displacement

Dear all,
In my FE model (pin on disc), I would like to define a contact property between pin and disc with a friction defination available in ABAQUS. I have assumed that friction coefficient depends on parameters like slip rate, pressure and temperature only. When i used friction coefficients with slip rate and pressure, model works without any error but if i use friction coefficients with slip rate, pressure and temperature, the model doesn't work and come up with following errors;

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Force integration from CPRESS is not equal to the Normal Load

Wed, 2011-05-11 15:52 - JLiu
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ABAQUS
contact
axisymmetric

Dear All,

I am running an axisymmetric model of a parabola tip on rigid surface contact under external load controlled by CLOAD. However, the CPRESS value outputed integraded over the annular areadoesnot equal to theexternal load inputed. The reaction force from the system does though.

I am suspecting that there is shaer component in the numbers given by CPRESS, but CSHEAR are all zero. Could anyone give me a hint on this problem.

 

Thanks a lot,

 

Jingjing

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Output of ABAQUS for contact of a rigid surface with a poroelastic layer

Mon, 2011-05-09 16:46 - RM
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Contact Mechanics Forum
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indentation
ABAQUS
contact
poroelasticm soils

Hello, I am modeling the spherical indentation of a poroelastic layer. I am modeling the indenter as a rigid analytical surface. As you know, the total pressure in a porous medium at each point is the sum of the elastic stresses from the matrix, and the pore pressure caused by fluid pressurization. Abaqus provides both the pore pressure and of course the rest of the stress quantities.

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A paper on ILS : Inequality level set : A new approach to handle inequality constraints

Fri, 2011-02-25 07:54 - Nicolas MOES
research
X-FEM
contact
level set
inequality constraint

Treating volumetric inequality constraint in a continuum media with a coupled X-FEM/Level-Set strategy

N. Bonfils, N. Chevaugeon, N. Moës

(accepted for publication in computer Methods in applied mechanics and engineering).

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Turning a shaft through conact pressure in ABAQUS/standard?

Sun, 2010-12-19 22:50 - hmpws
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Contact Mechanics Forum
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ABAQUS
contact
shaft

Hello all,

This is my first post here. This seems be an informative and helpful forum.

I am trying to model the rotation of a "hard" shaft as a result of motion of 2 strips of soft materials (please see attached figure).

The strips are deformed due to external forces and as a result, contact pressures are applied on the shaft. The forces are then varied on the strips leading to net rotational forces on the shaft.

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SPH modelling with LS-Dyna

Mon, 2010-12-06 09:52 - David MORIN
contact
LS DYNA
SPH elements

Dear all,

I'm using LS-Dyna and I would like to model the interaction between a viscous fluid  and metallic substrates.

If everything is working in 3D, it's not the same with the 2D...

Indeed I've used each contact algorithm (I think) in LS-Dyna and each time the contact between my 2D elements and the sph is not initiated.

Does anyone has an explanation to this curious problem ?

Maybe I'm not using the good contact setting.

Or contact between sph and 2D elements is not available in LS-Dyna.

Can you help me ? 

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Liming Jiang's picture

how to set the absolute contact stiffness when considering cohesive zone material (CZM)property

Fri, 2010-10-22 09:38 - Liming Jiang
research
contact
ansys
stiffness
CZM

I'm simulating the interface between a steel plate and the fire proof coatings covering the steel plate. The elements i use in the simulation is contact 173 with a material property of debonding,which is defined as cohesive zone model.(CZM)

 CZM in ansys provides  TBDATA such as maximum contact stress,contact at the completion of debonding, but what's the problem is that I failed to set the initial contact stiffness. it's true that ansys provides FKN to define the contact stiffness, but it's just a stiffness factor.

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Slope of Contact force Vs time curve too steep.

Thu, 2010-10-21 00:36 - priyadd84
research
ABAQUS
contact

Dear all,

           I did a 3 pt bending impact simulation with an elasto plastic model. But the slope of contact force vs time curve is too steep at the beginning of the impact. One trivial way of reducing the slope is by reducing the young's modulus of elements in the vicinity of contact or the impactor. Also reducing the mass of the impactor and the impact velocity did not help in reducing the slope.

Is there any other non-trivial parameters that controls the slope of contact force vs time plot? Thanks ina dvance.

 

 

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contact problem help in ABAQUS

Fri, 2010-08-27 01:22 - sanjay_2001
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contact
ABAQUS/CAE

i am new to Abaqus and i am unsing Abaqus 6.10

i planned to solve a contact problem by taking a bearing for example problem. i modelled the bearing section in pro-e and inmported it to Abaqus.

*i gave the material properties of steel for both ball and races

* in interferance i defined ball as master and the surfaces in the reces in the bearing as slave. frictionless.

* i gave pressure on the top race and arresteed the bottom race.

* the sides were given symentric with respect to y axis.

when solved i get the job is aborted.

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FSI Analysis to Understand Carpal Tunnel Syndrome

Tue, 2010-06-15 08:28 - ADINA Support
research
biomechanics
large deformation
contact
Fluid Structure Interaction
carpal tunnel syndrome

1. We present an interesting application of ADINA FSI in the study of carpal tunnel syndrome. The analyses involve large deformations and contact of multiple flexible bodies which are immersed in a fluid:

http://www.adina.com/newsgH71.shtml

2. Please recall that we offer a very attractive academic package, for research and teaching, for university users. For more information see

http://www.adina.com/educ.shtml

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Chris W Smith's picture

PhD position available on Contact & Frictional Joints in Gas Turbines, fully funded

Wed, 2010-02-10 06:31 - Chris W Smith
job
friction
contact
PHD position

This studentship has now been filled, but there may be further similar studentships to follow.

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

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ANSYS Modelling 3D Surface-to-surface Contact, need help

Wed, 2009-12-02 15:14 - pday
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Contact Mechanics Forum
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research
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large deformation
contact
3D

I am fairly new to ANSYS and have been trying to model the interaction between glass micro-spheres and silicone polymer micro-structures for my dissertation research.  I've been working through the online manual, but have been getting very odd results when running the simulation.  Any help at all would be appreciated.  The summary of my problem is as follows:

 Modelling:

It may help to first refernce the first two images at : http://bdml.stanford.edu/twiki/bin/view/Main/AnsysModelling

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Thermo-mechanical Modeling of Friction Welding

Mon, 2009-11-23 14:11 - ADINA Support
research
contact
welding
thermo-mechanical coupling
thermo-elasto-plastic

We present an application of ADINA in the thermo-mechanical analysis of friction welding. Please see: 

http://www.adina.com/newsgH61.shtml

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

http://www.adina.com/multiphysics.shtml

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Frictional Coulomb model in Abaqus

Tue, 2009-09-08 06:39 - Nicholas Fantuzzi
ABAQUS
friction
contact
interaction
model
frictional
coulomb
tangential
penalty

Hello everybody,

I'm trying to add friction in my model.Now I have a body that is simply supported in a direction (vertical) and free to move in another one (horizontal). I want to use Coulomb friction in the horizontal direction in order to reduce displacements in that direction.

I read Abaqus User's Manual vol5 30.1.5 (frictional behavior) and I followed commands written there, but I think that works only with multiple bodies and not with a single body. I'm using Abaqus 6.7-1.

Could Someone help me?

Many many many thanks

Nicholas

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jin haeng Lee's picture

Problem of contact data in ABAQUS 6.8 version

Thu, 2009-06-11 13:42 - jin haeng Lee
research
ABAQUS
contact

Hi.

I have an issue related to recent change in ABAQUS new version.

 I've recently found a problem related to cotact data in ABAQUS new version, 6.8. I use fil files, but I've heard from a Simulia engineer that data file also has the same problem (I have not checked it out yet.)

»
Lucia Nicola's picture

PhD position at Delft University of Technology, NL

Fri, 2009-02-06 05:06 - Lucia Nicola
job
computational mechanics
friction
dislocations
contact

We welcome applications for a 4 year PhD positon in the field of computational mechanics and materials science. Further details in the attachment.

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Surface Energies? Continuum Molecular Dynamics?

Thu, 2008-10-23 17:27 - Mike Graham
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molecular dynamics
contact
contact mechanics
continuum molecular dynamics
Lennard-Jones
van der Waals force

I recently encountered the research of Phil Attard and others, in which the contact problem is solved, relaxing the restrictions of the traditional contact models (Hertz, JKR, DMT) and solving based on a formulation where the governing equations are derived using finite-range surface forces and calculated numerically, self-consistently.

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Post-doc position on Multiscale Simulations of Cell Contact and Adhesion

Sat, 2008-04-26 22:12 - shaofanli
job
adhesion
computational mechanics
contact

A post-doc position on multiscale simulation of cell contact and adhesion shall be available this coming Fall at UC Berkeley. We are seeking for a person who has experience and background on finite element computations, especially in cell contact/adhesion modeling and simulation or finite deformation simulations.

Anyone who is interested in the position please send an email, resume, and reference to li@ce.berkeley.edu

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difficulties CONTACT problem with plasticity using ABAQUS FEA code.

Thu, 2008-04-10 12:41 - lazghabt
research
ABAQUS
contact
FEA
CShear

Hello everyone:

1.  I have built a FEM model 2D plane strain using ABAQUS/Standard (CPE4R) elements,

2. I am  modeling the contact between a cylinder and a plate in 2D.

3. The Cylinder material is given is ELASTIC ISOTROPIC material with no plasticit E=310 GPa

4.  The plate is with a Ramberg-Osgood plasticity with a Young's modulus E=210 GPa.

5. The mesh at the the contact point is VERY refined element characteristic length is about 1 micron. (My model units are  (mm,N,sec)).

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Murat's picture

2D Layout Optimization ( Nesting)

Sat, 2007-08-04 05:00 - Murat
Forums: 
Contact Mechanics Forum
Free Tags: 
contact

I am trying to setup a alghoritihm for nesting of 2D objects in a restricted area with minumum space left. For this purpose what kind of contact approach I should follow? Thanks already to whom may respond.

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