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Contact problem in NLGEOM

I am running an NLGEOM analysis with rigid impactor. I am not able to get contact behaviour properly, the contact id getting detected after certain intersection with the part.

I have sent the file through secure link. Kindly let me know about it.

I have run the same in radioss but would like to compare the explicit and implicit results.

Thank you.

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Altair Forum User

Hi Gopal,

I will check and update to you, thanks

gopal_rathore

Hi @Prakash Pagadala

Any update on the above points

Altair Forum User

Hi Gopal,

Did you convert the explicit deck from RADIOSS to OptiStruct?

Looks like some contact elements are lost during conversion. I am setting up again. Will update soon.

gopal_rathore

Hi Prakash,

I have made the deck in optistruct and there is no conversion involved from Radioss to optistruct

Thank you.

Altair Forum User

Hi Gopal,

Recreated the contact and this is the result, Do you have the same result?

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Considering the thickness, there is a gap of 2.35 at contact.

<?xml version="1.0" encoding="UTF-8"?>

gopal_rathore

Hi,

Kindly send the updated file. let me know about the changes done.

Also I want the contact with very less initial gap as this is a quasistatic run but the displacement observed is 50 mm and thus running it in NLEGOM subcase and when the impactor is rigid it creates problem in the same.

Thank you

Altair Forum User

Gopal,

I will share the file with you shortly by FTAM.

Have you tried with LGDISP?

gopal_rathore

Hi,

Thank you.
No I have not used LGDISPL. Kindly let me know about it also.

gopal_rathore

HI,

I can see intersection in the updated model during run. Also the impactor needs to be moving only in vertical direction.

Thank you.

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Hi Gopal,

Which version of HW are you using?

Does it happen at very begining? Can you share the result and .out files?

I ran the model which I shared and it does not penetrate.

gopal_rathore

Hi,

I am using 13 version. I have sent the files. Also the impactor needs to move only in vertical direction and thus I cannot make dof free for impactor rigid.

Thank you

Altair Forum User

Hi Gopal,

I will share large disp setup for the same model and it converges. Please check the results and let us know if you have any issues.

gopal_rathore

Hi Prakash,

NLOUT is not supported for 13 version I think. If possible, kindly send me 13 version file.

Altair Forum User

Gopal,

I suggest you to update to 2017 or 14.0 to use LGDISP.