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How to assign cohessive material to a surface?
Dear friends
I am modelling composite delamination using ABAQUS, i used 3D elementsin my model. my question is that how can i assign cohesive properties to a cohesive surface between to solids?
Should i treat the cohesive section like a continuum with thickness?
Is there any way exept the last one?
Is there any other aproach to model delamination?which one is better?
Thanks.
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Iman, I suggest reading
Iman,
I suggest reading 'Modeling adhesive joints and bonded interfaces' in ABAQUS/CAE user's manual (section 21.1 in V 6.8) and the following embedded topics.
Regards,
MZ
-Luck Is the Residue of Hard Work
Try using Abaqus 6.9
I use two dimensional models and I am able to model cohesive elements with zero thickness. I guess you could do that for 3-d models too. But this feature is available only in Abaqus 6.9 and not in previous versions.
Good luck,
Arun
Abaqus v6.9
If you are not using version 6.9, you can not model a cohesive behaviour @ interface suing Abaqus CAE. You'll have to do it by Abaqus script. But if you are using Abaqus 6.9, one can easily assign cohesive behaviour @ the interface even in 3D. I've dont it
best Regards,
Venkat Bharath,
5th year Student,
Department of Civil Engineering,
Indian Institute of Technology, KharaGPur.
India
bharath1911@gmail.com
energy balance/surface-based cohesive of composite under impact
Hi there! I am really new to Abaqus and I need to model a composite
laminated crash cone under impact to a flat solid wall (analytical
surface is used). I modelled a cone with a layers of conventional shell
elements with hashin failure criteria and surface-based cohesive
behaviour as interaction between layers representing the interface of
composite laminates. The model runs successfully but once I checked the
energy balance, the damage dissipation energy from the cohesive, it
turned out to be NEGATIVE (I think this is wrong).
I tried to model a simple geometry model with cohesive elements and the
damage energy from cohesive element is POSITIVE (which seems to be
correct).
As far as I know the energy balance: internal energy =
strain energy + artificial energy + damage dissipation energy + penalty
contact energy +contraint penalty energy + plastic energy
where Total energy = internal energy + viscous energy + kinetic energy + frictional energy + external work = constant
I set up another history field output request to capture the energy of
hashin damage to compare with the all damage energy of model and the
result is that damage from surface-based cohesive is NEGATIVE. This
means the more damage to the cohesive, the less internal energy in the
cone which means that less energy absorbed from the impact. <--
totally wrong...
Due to the complex geometry of the model, cohesive element does not seem to the one I can apply to my model.
Could anyone explain or give me a solution why the damage energy from surface-based cohesive is NEGATIVE? Is it wrong?
Here is the interaction property of the surface-based cohesive
** INTERACTION PROPERTIES
**
*Surface Interaction, name="interface prop"
*Cohesive Behavior, eligibility=ORIGINAL CONTACTS
20000.,15000.,15000.
*Damage Initiation, criterion=QUADS
60.,90.,90.
*Damage Evolution, type=ENERGY, softening=EXPONENTIAL, mixed mode behavior=POWER LAW, power=2.
0.6,2.,2.
*Contact Damping, definition=CRITICAL DAMPING FRACTION
0.1,