Large Displacement Problem

Altair Forum User

I have a question about how we should set instruction in large displacement contact problem.

 

Group → TRACK → FINITE

          →DISCRET → N2S

 

EXPERTNL→ AUTO

 

CNTSTB→ YES

 

My solution is to used this instructions now.

 

Do I forget about the large displacement problem?

 

And why N2S not supported nonlinear material and geometric nonlinearity?

 

In help it write this → Additionally, only sliding contact without friction is currently supported. Also, no nonlinear material and geometric nonlinearity are allowed.

Altair Forum User

Hi @LKZ

 

If you think relative motion between master and slave surfaces is more than a fraction of their element sizes, then use FInite sliding, (TRACK- FINITE)

When the slave or master surface includes corner, the discretization is suggested to be N2S, S2S is usually more expensive than N2S in both space and time, but it could produce smoother contact pressure in many cases

 

For N2S contacts in large displacement analysis and S2S contacts in small/large displacement analysis, using PARAM, EXPERTNL, CNTSTB activates the stabilization parameters used in CNTSTB

 

Altair Forum User

@Prakash Pagadala Thanks to your reply.

 

I want to ask CNTSTB in the load collector setting and in the control card.

 

Are they same? or I should set all of them.

Altair Forum User

@LKZ

 

I hope this helps:

 

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Altair Forum User

@Prakash Pagadala Thanks for you.

Altair Forum User

@Prakash Pagadala I have a new question.

 

When I do the analysis. At the same model the large displacement will spent more memory.

 

My analysis large displacement spent about 34GB and small displacement spent about 29GB.

 

They have 5GB's difference. 

 

Why large displacement analysis spent more memory?

Altair Forum User

@LKZ

 

Both are different formulation and memory requirement will be different, 

Altair Forum User

@Prakash Pagadala Thanks to your reply.

 

I got it.