type 2 interface

Altair Forum User

I am getting some errors “ negative mass on node” and some warnings “check tied interface”. On checking the nodes by ID I can see that these nodes are on the master contact surfaces of TYPE 2 contact with SPOTFLAG=0.

when I set SPOTFLAG=1, simulation can continue to work, it cause a relatively important added mass (mass error=0.15, it is unaccptable) from 1st cycle to last cycle.

I read some discussions about this issue in the forum, but I can not find an answer that can solve the problem.

  So, anybody can help me?

  Thank you very much!

Altair Forum User

Hi Zhang,

When option Spotflag =1 is used in the Interface Type 2, it is expected that there are added mass on master nodes at the first cycle of RADIOSS Engine.

Is it possible to share your files (starter, engine and out files)?.