Superelement Model Conversion

Altair Forum User

Hi

I've a superelement model in nxnastran and i'd like to convert it for optistruct format (16bit) with different units (from mNN mm to N mm)

Any suggestions? Regards

 

 

Altair Forum User

Hi,

You can directly work on Nastran file in OptiStruct profile and save as .fem (OS) file and can run the analysis. There is no conversion required for Nastran file to OptiStruct.

User has to follow a consistent unit system. If user want to follow  N mm unit system, user has to change the unit system manually and has to follow a consistent unit system.

The basic consistent unit system followed is attached along.

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

Altair Forum User

How to do? I have an .txt and .pch

 

I want to change from mN-mm to N-mm

Regards

Altair Forum User

Hi,

You can include the pch file. In Analysis> Control cards> Include_Bulk, provide the path to and the name of the file to be included.

1mN-mm is 0.001 N-mm. 

There are many online unit converter tools available. Update all the units (Rho, E...etc) accordingly to the unit system followed.

Altair Forum User

Thanks George,

 

I know 1mN-mm is 0.001 N-mm but I don't know how to reconvert manually the .pch file? Do i need to change the value for any single KGBOX manually?

Example 

mN-mm

 

DMIG*    KGBOX                     12522               2
*                   12521               1 6.307481517E+04
*                   12521               2-1.745010826E+04
*                   12521               3 1.500132835E+05
*                   12521               4-8.455473220E+06
*                   12521               5-1.979675434E+06
*                   12521               6-1.243141111E+06
*                   12522               1-1.561769361E+09
*                   12522               2 3.627508327E+08
*                   12522               3-1.243141111E+09
*                   12522               4-1.979675434E+10
*                   12522               5 4.110513817E+11

 

I wanto to change in N-mm. I have to change manually the values?

Regards

 

 

Altair Forum User

Thanks George,

 

I know 1mN-mm is 0.001 N-mm but I don't know how to reconvert manually the .pch file? Do i need to change the value for any single KGBOX manually?

Example 

mN-mm

 

DMIG*    KGBOX                     12522               2
*                   12521               1 6.307481517E+04
*                   12521               2-1.745010826E+04
*                   12521               3 1.500132835E+05
*                   12521               4-8.455473220E+06
*                   12521               5-1.979675434E+06
*                   12521               6-1.243141111E+06
*                   12522               1-1.561769361E+09
*                   12522               2 3.627508327E+08
*                   12522               3-1.243141111E+09
*                   12522               4-1.979675434E+10
*                   12522               5 4.110513817E+11

 

I wanto to change in N-mm. I have to change manually the values?

Regards

 

Any idea?

Regards

 

Altair Forum User

@bmech

 

There is no way to change the units in OptiStruct. you may have to do it manually.