Any suggestion on output field data in local coordinate system?

[LangmuirL]

I've tried both *Orientation and *Transform but they seem not like working for my problem. I need the field output, for example, radial displacement, in the cylindrical coordinate so that I could directly read it from odb by writing script without launching CAE. Any thoughts? Thanks.

Lang

 

[akabarten]

Hi Lang,

Option you are looking for is related to *NODE OUTPUT keyword.
You need to use *NODE OUTPUT, GLOBAL=NO, by default GLOBAL option is set to YES.
In this case the output will be save in coordinate system from *TRANSFORM card.

Regards,
Bartosz

 

[LangmuirL]

Thanks, Bartosz. I've done this using the script to transform the coordinate for output, but you gave an easier way!

Lang

 

[LangmuirL]

Hi, Bartosz

Got a new problem while I try to change odb coordinate by writing script. Since the odb is read only there is no way to save the transformed coordinate in odb. Everytime you attempt to do it, then a lck file is generated. This is very annoying in my case. Do you have any idea of how to avoid it?

Alternatively, I tried your method by adding *transform and changing *node output in the original Inp file. However, the boundary condition for computation seems being changed at the same time while the outputs are still in the global coordinate. I read the documentation serveral times but I'm still not sure if I understand this part correctly. My intention is only to transform the output in Cartesian system into cylindrical coordinate system...

Lang

 

[IceBreakerSours]

You can do it in the Viewer. I don't recall it off the top of my head but you can choose to view your results in a Cylindrical coordinate system (or some other coordinate system that you make) in the Viewer.

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[LangmuirL]

Thanks, IceBreakerSours,

The problem is that I need to output those field values in a text file for the further processing it by other software. And it should be transformed in the local coordinate first....

 

[LangmuirL]

For a better description of my problem, I would like to present my script here.

from odbAccess import*
odb=openOdb(path='MembraneTest.odb', readOnly=True) #odb
step1=odb.steps['Loading'] #step
node1=odb.rootAssembly.instances['PART-2-1'].nodeSets['MEMBRANE_SIDEX']
outputFile=open('output.dat','w')
coordSys = odb.rootAssembly.DatumCsysByThreePoints(name='cylC',
coordSysType=CYLINDRICAL, origin=(-1000,-1000,0),
point1=(-999,-1000.0, 0), point2=(-1000.0, -999.0, 0.0) ) #coordinate
frameRepository=step1.frames #temporary variable to hold the frame repository
numFrames=len(frameRepository) #total frame number
for i in range(numFrames):
frame=frameRepository
u=frame.fieldOutputs['U'] #variable
u_at_node=u.getSubset(region=node1)
cylindricalDisp = u_at_node.getTransformedField(
datumCsys=coordSys)
Time=frame.frameValue
for uVal in cylindricalDisp.values:
outputFile.write('%1.1E\t'%Time)
outputFile.write('%E\n'%(uVal.data[0]))
outputFile.close()
odb.close()

the line of highlight can only be run for the first loop. It stops when it is being read again. Very strangely, sometimes, but at a very low chance, the computer managed to run through the whole loop, but most time it crashed. This is very frustrating as I need this script to work with tons of odb files. Can anybody give any suggestions?

Lang

 

[IceBreakerSours]

I would simply extract field variables and import them in to Matlab or equivalent and do the transformation in there.

Are you new to this forum? If so, please read these FAQ:

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[akabarten]

Hi Lang,

Sorry I must be blind, GLOBAL options works only with history output.
I see you have field output now.

As I know filed output can be save only with global coordinate system.
You can transform the output with Abaqus/Viewer.
I never used the option so I can only give you documentation chapter:
Abaqus/CAE User's Manual, 42.6.8 Transforming results into a new coordinate system

Regards,
Bartosz