Press metal into silicone

[2lai]

Hi,

I have a simple model consisting a 0.1mm thick, 2mm wide and 10mm long busbar in contact with a 0.3mm thick, 10mm wide and 10mm long silicone. After applying 14psi pressure on busbar, it should penetrate into the silicone. The silicone is modeled as a mooney rivlin material. The boundary condition is fixed back surface of silicone.`Unfortunately, it does not work.

Could you please help me how to build a correct model? Thanks a lot.

 

[kellnerp]

What doesn't work?

Where did you get the Mooney Rivlin parameters?

How are you modeling the contact?

Did you try it using a Linear Isotropic material for the silicone rubber first as a trial run?


TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."

 

[2lai]

After applying pressure, 0.1mm thick metal should be pushed into silicone for 0.1mm deep. However, the solution is not converged.

 

[kellnerp]

What doesn't work?

Where did you get the Mooney Rivlin parameters?

How are you modeling the contact?

Did you try it using a Linear Isotropic material for the silicone rubber first as a trial run?


TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."

 

[rstupplebeen]

Try displacing the busbar then back out the force required. Displacement controlled simulations are in general more robust because there are no unconstrained DOFs. I hope this helps.

Rob Stupplebeen

 

[2lai]

Thanks for the input.
(1) The Mooney Rivlin parameters were obtained from the rubber, 1st material=800 psi; 2nd material=200 psi. I don't think it represents silicone rubber.

(2) It seems that linear isotropic material model is better than Mooney Rivlin model for silicone rubber, although the solution is still like "failure" --- the solver should stop at time=1s, however, it is stuck at 0.965s.

(3) The model is like 10mm wide silicone on 2mm wide silicone on 10mm wide silicon. The contact sets are defined as silicone rubber (mesh size=0.2mm) to silicon and to busbar (mesh size=0.1mm). It seems that the program has problem to solve the contact problem. Any suggestions?

(4) Displacement controlled simulation does not go through.

(5) Some questions about force controlled simulation (a) Does increasing the Singularity-elimination-factor (=0) or raising the convergence tolerance help? (b) Does switching target and source help? BTW, which color (pink/blue) is (target/source)?

 

[kellnerp]

You can start out by running a linear static analysis with contact.

I would use surface to surface contact.

You will likely have singularities at the edges where the materials come together. You will know this by looking at the stress plots. If there are high stresses right at the edge where one piece contacts the other that is a singularity.

I believe there is some method in Cosmos/M to obtain the Mooney Rivlin parameters. Read the docs. I wouldn't just use the rubber params without know what they represent.

TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."