Learning Forum

[pdsamuel]

Hello, I have been trying to use tiebreak contact (CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TOSURFACE_TIEBREAK) [Option 9] with the 20 noded Hexahedral solid element (ELFORM 23). When I select the surfaces using the segment set approach- it keeps giving me an error that certain master, slave surfaces have not been not found. Because this didn't work, I then tried defining tiebreak contact using the PARTIDs. But, with this approach the nodes on the middle of the edges don't get selected and only the nodes on the corners are tied. I strongly prefer to use the segment set selection of tiebreak surfaces, and need to know to how to execute this for the 20 noded hexahedral elements.

Also another associated issue is that when I use a regular a contact definition between two hex elements and apply a closing/compressive load, there is interpenetration at the middle nodes (i.e. the nodes in the middle of the edge)- which should not occur.

Can anyone share from LSDYNA support/community help figure a solution to these problems? Thanks

[Reno Genest]

Hello,

Which version of LS-DYNA are you using? Could you post images showing the problem?

 

Reno.

[pdsamuel]

The problem that occurs when using PART ID definition of the tiebreak contact- All the nodes of the element are not being tied (only the corner nodes).

 

[pdsamuel]

The error message that shows up when using segement set ID for definition of tiebreak contact. It is not able to detect the element now. 

[Reno Genest]

Hello,

Could you send your test model to your Ansys account manager? He will forward it to me and I will have a look.

Thanks,

 

Reno.

[pdsamuel]

Hello Reno Genest, What is the correspondence email to send the model to you? Additionally, I am facing a different problem when using the 20 Hexahedral elements. Of late I have been experiencing the error as "negative determinant, check element connectivity' using these 20 Hex elements. Please help. Thank you!

[Reno Genest]

Hello,

Please contact your Ansys account manager to send us the model. What is the name of your organization?

Also, note that Ansys employees are not allowed to upload and download files on the Ansys Forum.

 

Let me know how it goes.

 

Reno.

[pdsamuel]

Hi Reno,

This issue still doesnt seem to have been fixed:

Hello Reno,

I am still dealing with this issue. Does Ansys have a solutipn to this?

"I have been trying to use tiebreak contact (CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TOSURFACE_TIEBREAK) [Option 9] with the 20 noded Hexahedral solid element (ELFORM 23). When I select the surfaces using the segment set approach- it keeps giving me an error that certain master, slave surfaces have not been not found. Because this didn't work, I then tried defining tiebreak contact using the PARTIDs. But, with this approach the nodes on the middle of the edges don't get selected and only the nodes on the corners are tied. I strongly prefer to use the segment set selection of tiebreak surfaces, and need to know to how to execute this for the 20 noded hexahedral elements."

Please help.

Thanks,

[pdsamuel]

Hello!

Can someone from ANSYS please respond here?

Thanks

[rgenest]

Hello,

I am not getting notifications since the Forum moved to the new Innovation Space website. Could you create a support case on customer.ansys.com or innovation.ansys.com and send us the model? If you are an academic customer, please let me know the name of your organization and I will contact your account manager to get the model this way.

Note that Synopsys employees are not allowed to download and upload files on the Forum.

Have you tried with the latest releases R16 and R17 of LS-DYNA?

Reno.

[pdsamuel]

University of Delaware. Deavon Church is the contact point.

[rgenest]

Hello,

Thank you. I was able to find your contact point at your University in our database and I just sent him an email. You can check with him to send us the model.

 

Reno.