Contact Friction Coeff

[Bayram2014]

Dear all,
I am using abaqus for modeling a friction problem between two deformable bodies.
My question is that I am using and exponential decay friction law, means that the fric coeff depends on the slip rate.
*Friction, slip tolerance=0.001, exponential decay
0.9
0.12, 3.0e-9
0.1

I made some postprocessing and got all the contact variables on a line on the contact surface. I wanted to see how the friction coeff varies with
contact status and plot CSHEAR1 = f(CPRESS)
or CSHEARF = f(CNORMF) ....
the result is always: an increasing frction coeff that stabilizes at 0.9 when sliding and never decreases.
It is strange because I have sliding at the end of my computation but the CSHEARF/CNORMF = 0.9 = CSF1/CNF1

Thank you for any help.

Bayram

 

[FEA way]

Start from a simple model (like two blocks on top of each other) to see how exactly this option works. Make sure that you use good meshes and that contact is properly established (no gaps and so on).

Apart from that, you may want to check example files in Abaqus documentation (Verification Guide). There are some examples specifically for exponential decay.

 

[Bayram2014]

Heloo again,
I would like to know the formula relating the friction coef to slip rate when
considering Exponential decay friction model with test data points.
regards,
Bayram

 

[FEA way]

Check the documentation chapter "Interactions —> Contact Property Models —> Mechanical contact properties —> Frictional behavior —> Using the basic Coulomb friction model —> Specifying static and kinetic friction coefficients". There you should find the relevant information regarding this type of friction definition.

 

[Bayram2014]

Thank you for your reply, but before asking I have checked all the documentation and could not find the answer.
I have read section 37.1.5 of the user analysis guide.
regards