Surface-based cohesive behavior in Explicit 1

[Utie]

Hi everyone,

Currently I am working on a micro-mechanical model of a single fiber in an epoxy system under dynamic conditions. I would like to model the debonding at the interface when submitting the RVE to a uniform compression. Using cohesive elements the results are inadequate: we get penetration of the matrix into the fiber because of the extreme loading conditions. That's why I opted for surface-based cohesive behavior. Penetration is impossible and yet the traction-seperation response can be accurately captured. This behavior was verified under quasi-static conditions (Abaqus/Standard). Now I would like to convert this to an Explicit problem, but the following error occurs:

"The interaction "Int-1" references a contact property (IntProp-1) that contains the damage or cohesive behavior option. These options cannot be specified for this type of interaction."

I would like to use a bi-linear traction-separation model with the Max. Stress damage initiation criterion. For damage evolution we have a fixed fracture toughness. Neither general contact or surface-to-surface contact works. The Abaqus version is 6.12. According to the manual cohesive behavior is possible in the Explicit module, so can anyone give me any advice on how to do this? I attached the .cae file since I cannot run the simulation yet.

Regards,
Utie

 

[Mohcine]

Hi,
Please help us, I'm experiencing a similar problem. I'm modelling the impact between a impactor and a laminated composite with 8 plies. The cohesive interaction between the plies are giving me the same error .

Utie,
If I managed to solve it , I will post the solution here .

 

[IceBreakerSours]

I can't seem to open the file. INP will help.

My guess is that there may be an issue with the chosen contact formulation. ABAQUS Analysis User's Manual says the following:

"Surface-based cohesive behavior is enforced only for node-to-face contact interactions in Abaqus/Explicit and is not available for edge-to-edge and node-to-analytical rigid surface contact interactions."

See section 35.1.10 Surface-based cohesive behavior for details.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[Utie]

Dear IceBreakerSours,

I guess you meant section 36.1.10 Surface-based cohesive behavior. I couldn't agree with you more. However, the manual also states (37.2.1 Contact formulation for general contact in Abaqus/Explicit) how pure master-slave weighting for node-to-face contact can be specified. I'm not sure if I defined this contact in a wrong manner, but this method doesn't seem to be working. I attached the .inp file. Thank you for your help!

Regards,
Utie

 

[IceBreakerSours]

Nope, I meant 35.1.10 (as per ABAQUS v6.11pr3).

However, the manual also states (37.2.1 Contact formulation for general contact in Abaqus/Explicit) how pure master-slave weighting for node-to-face contact can be specified.

Correct, but it does not refer to surface-to-surface contact, which is what you have defined in your model. Besides, it does not seem like there is going to be any self contact in your problem or do you expect it based on previous runs or experience?

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[Utie]

Besides, it does not seem like there is going to be any self contact in your problem or do you expect it based on previous runs or experience

No, self-contact is absolutely not an issue.

The problem however is to correctly define the node-to-surface contact problem. I use the CAE to define the contact problem: Create interaction -> General contact (Explicit). In the Contact formulation tab I select the Pure master-slave assignment. No matter what I select in the Contact domain, the program will return an error. What am I doing wrong?

 

[IceBreakerSours]

I do not see obvious mistakes. In fact, everything seems to be set correctly. Have you tried looking at Simulia's customer help website? You'll need to register and use keywords to search for answers.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[IceBreakerSours]

Try this link as well.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[isyhadh]

may I know what is your material involved?
is it GFRP? your value of Knn, Kss and Ktt must be correct as you modelled in microscale? is it comparable?
and also, your mesh at the interaface must be very fine, between the surfaces of contact
also varying the time of contact and force will do some difference, from my experience

this is zero thickness interaction cohesive, right?

 

[Mohcine]

Utie,
How many interactions properties do you have defined?

 

[bornvirgo85]

Hello,
I am not sure if you have resolved this issue but I will mention a few comments.
(1) Are you modeling in 2D or 3D using Abaqus/explicit? In Explicit, you need to define general contact domain for cohesive surface interaction. In the Material module, when you select COHESIVE, do not select *Specify bond set using Surface-Surface in Std*. Keep the options as default and specify the properties.

(2)If rigid surfaces are in contact with the deformable body, then the rigid surfaces are defined as discrete elements.
I am hope these comments help.

I am having an issue in trying to model cohesive surface interaction between a rigid discrete surface and a deformable body in 2D in Explicit using General Contact Domain. Abaqus keeps giving an error that *Contact does not support the use of 2D surfaces. I presume this is a limitation of the software but the manual does not explicitly mention that cohesive surface interaction cannot be modeled in Abaqus/Explicit in 2D. Also, all the example and benchmark manuals have used cohesive interaction in Explicit in 3D only.

Please advise. Your help is greatly appreciated!

Thank you
Swapnil