TIME STEP LESS OR EQUAL ZERO

Altair Forum User

Hi,

i'm trying to simluate an carbon fibre crash structure with RADIOSS V10.
The calculations are stopped with the error message: 

 

NODE       7501 DE-ACTIVATED FROM INTERFACE

  **ERROR : TIME STEP LESS OR EQUAL ZERO

 

What does that mean? What do i have to do in order to solve this Error?

Thank you in advance!

SeKar

Altair Forum User

Hi Sekar,

 

Does your model have contacts?

 

can you share the complete out file?

Altair Forum User

Thank you for your fast reply. 
I'm an absolut beginner in the world of simulations. That's why i am thankful for every help and support!
Attached to this post is the OUT file. 

 

I haven't created any connections between the layers. I only created a contact interface.

Please let me know if you need any more information.

 

Unable to find an attachment - read this blog

Altair Forum User

Okay, 

 

what type of contact are you using?

 

can you increase the gap between the components with contact surfaces and check if that helps?

 

if you are using type 7 contact can you check with a gapmin= 0.1 or up 0.5?

Altair Forum User

I'm using contact type 7.

Thanks to an other helper (Employee of Altair - not sure if i'm allowed to say the name..) i finally got the solution. My mistake was in the contact interfaces:
Changes were done in the following categories:
* stiffness definition
* Node and segment deletion
* friction penatly formulation

Furthermore the engine file was adjusted: the scale factor and the minimum time step have been decreased.

But thank you Prakash Pagadala for your fast help! 
 

Altair Forum User

Sekar,

 

can you share more information on how you change the friction penalty formulation?

 

Thanks

Altair Forum User

increase the Gapmin. then it will work.

 

this is because of negative volume happening due to the contact.