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Contact simulation, no preprocessor

Experimenter
Experimenter

Hi everyone,

 

I'd like to define a press-fit contact. I have NO preprocessor but I already have the geometry of my model (as a text file containing nodes and elements). So I read the documentation (Quick Reference Guide and User's Guide) and added the necessary entries but I always got a fatal error:

 *** USER FATAL MESSAGE 316 (IFPDRV)
     ILLEGAL DATA ON BULK DATA ENTRY BCTSET  
 BCTSET  101     20      10    

 

Here's the content of the file I run:

SOL 101
CEND
ECHO=NONE
BCSET=101
PARAM,PRGPST,NO
SPC=1
$
BEGIN BULK
$-------1-------1-------1-------1-------1-------1
BCPROPS	10	1000
BCPROPS	20	2000
$-------1-------1-------1-------1-------1-------1
BCTSET	101	20	10
$-------1-------1-------1-------1-------1-------1
SPC1	1  123456	2000682	thru	2001363
INCLUDE path of the shaft
INCLUDE path of the hub 
ENDDATA

So I guess I'm wrong about how BCSET and BCPROPS work together. I also would like to find a way to indicate the press-fit contact, but I think this is not a problem, I just have to use either the cards MIND1 and MAXD1 of the BCTSET entry or the card OFFSET of an additionnal BCRPARA entry.

 

 

So I would like to know what I am doing wrong. A possibility would be to generate the text file with a preprocessor but I don't have any. So feel free to do it for me, or just tell me where I'm wrong Smiley Wink

 

I'm using CTETRA elements with 4 nodes.

 

Thank you in advance Smiley Happy

 

gm

4 REPLIES

Re: Contact simulation, no preprocessor

Siemens Phenom Siemens Phenom
Siemens Phenom

Illegal data type errors from the IFP (Input File Processor) module indicate a problem with the data on the specific card. Typically, this means a real value is supplied where an integer is expected; and integer value is supplied where a real is expected, or a required field is empty.

 

In the example given, your BCTSET card has data for fields 1-4 only

 

See Remark 6 for BCTSET (particularly the first bullet):

 

6.The following rules apply to MINDi and MAXDi:

  • Both default to 0, but at least one must be explicitly defined as non-zero.
  • MAXDi must be greater than MINDi (MINDi<MAXDi).
  • Negative values are allowed.

Re: Contact simulation, no preprocessor

Experimenter
Experimenter

Hi Jim,

 

Indeed, I did not consider that at least MIND1 or MAXD1 must be defined... So now it works. Thanks a lot !

Re: Contact simulation, no preprocessor

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

You say you are using 3-D Solid CTETRA 4-nodes elements: well, for contact analysis is extremely important to use high-order elements, this is critical to account for accurate results, TET4 elements are "constant strain & constant stress" tetraedral, then better to use parabolid TET10 elements.

Also, the use of high-order elements with midside nodes located in the surface geometry will avoid undesired initial interference between corner-only nodes.

initial_penetration0.png

To learn more about how to solver "interfernce-fit" problems using NX NASTRAN please visit my blog in the following address: https://iberisa.wordpress.com/2012/01/16/tratado-completo-sobre-como-resolver-problemas-lineales-de-...

Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Contact simulation, no preprocessor

Experimenter
Experimenter

Hello Blas,

 

Thanks a lot, I will follow your advice. Thank you for the link to your blog too !

 

Best regards,

 

gm