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DC-FSI error of undefined external node

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Hello everyone,

I followed the procedures for  5.13 ACU-T: 5403 Piezoelectric Flow Energy Harvester: A Fluid-Structure Interaction in AcuSolve tutorial to do a DC-FSI analysis.

However, I had errors "ERROR: Undefined external node" for all the nodes in the coupling surfaces in OptiStruct model.

I attach the log file and inp file here.

Does any one know why this happen?

Thanks a lot!

DC_FSI_Practice.8.Log DC_FSI_Practice.inp

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I just ran through this tutorial, and it seems to work correctly as written.  (I did notice that you had left Simple BC active for the Beam surface, where it should be inactive/off since it's handled by the External Code Surface command.  In any case, it still ran when I did leave it active as you had it.)  Is it possible you assigned the BCs to the wrong surface sets?

 

Can you attach the slab_dcfsi.out and cci.txt files from your run?

 

Which versions of AcuSolve/OptiStruct are you using?  (I have HyperWorks CFD Solvers 2019.1 and HyperWorks Solver 2019.2.)

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Thanks acupro,

I updated OS to the 2019.2 and it works now.

However, I met a new error:

acuSolve: *** TCP socket write error; Permission denied
acuRun: *** ERROR: error occurred executing acuSolve

Do you know what is the reason for this error?

BTW thanks for telling me that I didn't turn off the Simple BC for beam.

Thanks!

And I really appreciate your help!

001TRY.fem 001TRY.inp 001TRY.6.Log MESH.DIR.zip

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I'm not very good on the OptiStruct side, but apparently the OptiStruct side has finished and closed the connection to AcuSolve.  I now see you've made changes to the tutorial model - or whichever model you're running.  But whatever you've done on the OptiStruct side does not appear to be consistent with what you've done on the AcuSolve side.

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error.thumb.PNG.cbde21448cf72d9f30bcfacf0bea5af6.PNGhello everyone,

I have to run a tutorial about Direct Coupling Fluid structure interaction between Acusolve and optistruct.It is not the  Piezoelectric Flow Energy Harvester one but it is a similar to this.

I got an error in Acusolve which is "unable to match with the external surface at 22 quadrature points".

Do you know what is the reason for this error ?

Can Anyone help me please ?

thank you in advance !!


 

 
 
 
 
 
 

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That generally means the surfaces on the AcuSolve side and the OptiStruct side are not co-located.  Make sure both models have the DC-FSI surfaces in the same location and are the same size/scale and shape.  Just above the assertion you have in the Log file:  Ave distance = 9.367829e-004; Max distance = 2.350710e-002.  This means the maximum distance between the OptiStruct and AcuSolve surfaces is 2.350710e-02, larger than the Max allowed gap of 5.486660e-003.  Check to ensure the surfaces are the same size, shape, and location in both models.

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