TRANSIENT DIRECT
Hi, I must perform a TRANSIENT DIRECT ANALYSIS in Optistruct.
I have to give a linearly increasing acceleration up to a constant value to the structure (equal to 20g --> GRAV load) in the constrained zone (like an earthquake). For TSTEP and TABLED1, i ve no problem. I ve setting the parameters on the TLOAD1 card like in the attached figure, but my analysis don' t run. This is the error:
*** ERROR # 2094 ***
EXCITEID on TLOAD1 # 4 data references nonexistent
SPCD # 5.
************************************************************************
A fatal error has been detected during input processing:
*** ERROR # 2094 ***
EXCITEID on TLOAD1 # 4 data references nonexistent
SPCD # 5.
Where am I doing wrong ? <?xml version="1.0" encoding="UTF-8"?>
Answers
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Hi,
GRAV load collector type is not supported with TLOAD1. Please use SPCDs to apply acceleration load
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perfect,
i want to impose the acceleration (20 g amplitude on x DOF with a ramp funcion from zero to max) on constrained nodes.
Is it correct to costrain all DOFs nodes with SPC and applying on the same nodes SPCD on x DOF?
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Hi,
Are you trying to do something like this?
This results in zero deformation.
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Hi Prakash
As you said gravity loading doesn't work with tload1, but what if we keep the type of load default instead of defining it as acceleration. I think this could work.
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Altair Forum User said:
As you said gravity loading doesn't work with tload1, but what if we keep the type of load default instead of defining it as acceleration. I think this could work.
I think it should work. But GRAV with acceleration as load type it may not work.
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Thanks Prakash,
yes the input is like in my case,with one difference:
- I want all DOFs fix in one surface (SPC all fix).
- I want an acceleration (from 0 to 20 g) in the same surface (SPCD in x DOF).
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So it is like you are trying to apply acceleration on rigid nodes.
This will result in zero deformation.
It would be better if you can share the model to get it better what you are trying to do
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I ve this situation:
<?xml version="1.0" encoding="UTF-8"?>
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Can you check the results, please?
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stress level is ok (i ve check this, with a Response Spectrum Analysis), but my body have a rigid body motion on x direction.
I ve performed this setting:
(consistent unit are: ton - mm - sec - N - MPa).
<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
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Hi,
Can you share the model file, please?
Please use the file transfer link in my signature to share the model file
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Altair Employee
