negative node stiffness error

Altair Forum User

Hi i'm getting negative node stiffness error in radioss block .  i'm doing simple top load analysis  using MAT15 orthotropic material model using shell elements. please let me know how can i resolve

Altair Forum User

Hi,

 

Are there any type2 or type7 contacts in your model?

 

If you have type2, set SPOTFLAG=0 

Altair Forum User

yes i'm using both type 2 and type 7. for type 2 spot flag is 0

Altair Forum User

with type2 with spot flag set to 0 you still face the same error?

 

can you also change STFAC in type 7 to 1 and run the analysis?