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Abaqus, distributions of thicknesses and plies

Abaqus, distributions of thicknesses and plies

Abaqus, distributions of thicknesses and plies

(OP)
Hi. I am using Abaqus to perform an anlysis on a variable tow angle laminate, and I am having some problems when I start the simulation. The errors are:
1) THE DEFAULT SHELL THICKNESS DEFINED IN DISTRIBUTION ASSEMBLY_PART-1-1_PART-1_THICKPLY1 MUST BE POSITIVE AND HAVE MAGNITUDE GREATER THAN MACHINE PRECISION
2) 81 elements have missing property definitions. The elements have been identified in element set ErrElemMissingSection.

I have attached the .inp file to this thread, in case you want to give it a look:
Open Abaqus, click on 'Import', then 'Model', select the .inp file extension and then select 'SSSS-0000-000VAT.inp'.

Here's the link to the file:
https://files.engineering.com/getfile.aspx?folder=...

Thank you in advance.

Edit: for now, the simulation regards a plate made by only one ply, of thickness 1 mm. the thickness is supposed to be constant along the surface,
while the rotation angle of the ply changes along it.

RE: Abaqus, distributions of thicknesses and plies

Just change the value that you specified as the default one in distributions from -99999.99 to something more realistic (it can be the same or similar to other values defined in the distribution) and it will work.

RE: Abaqus, distributions of thicknesses and plies

(OP)
@FEA way
How do you change the default value?

RE: Abaqus, distributions of thicknesses and plies

In the input file you can specify it using the first line of *Distribution keyword, with an empty space instead of an element number. For example:

*Distribution, name=PART-1_ORIANGLEPLY, location=ELEMENT, Table=PART-1_ORIANGLEPLY_Table
, 150.
1, 165.
2, 165.
3, 165.
...

In this case 150 will be the default value.

RE: Abaqus, distributions of thicknesses and plies

(OP)
@FEA way
Ok. What about the elements? How can I define them in sets before giving them to the *distribution? As you can see in my file, I have put the elements in the distribution in a very non-efficient way. For example, instead of:
1,165
2,165
3,165
4,165
something more convenient would be:
set name, 165

RE: Abaqus, distributions of thicknesses and plies

This can be easily done in Abaqus/CAE, then you could export the input file and keep working with it using a text editor.

RE: Abaqus, distributions of thicknesses and plies

(OP)
@FEA way
I've already tried exporting the interested sets, and put them in this shape in the .inp file:
*Elset, elset=SETVAT1, instance=plate-1
1, 2, 3, 4, 5, 6, 7, 8, 9

or :

*Elset, elset=SETVAT1, instance=plate-1, generate
1, 9, 1

and I put the instruction right before the *Distribution, and wrote 'SETVAT1,165' in the *Distribution, but it gave me the following error:
'Unknown assembly level element set SETVAT1.'




RE: Abaqus, distributions of thicknesses and plies

Try exporting the input file without the use of instances (there is an option for that in Abaqus/CAE when you enter Model Attributes).

RE: Abaqus, distributions of thicknesses and plies

(OP)
@FEA way
I removed all the instances names, and obtained expressions like this:
*Elset, elset=SETVAT1, generate
1, 9, 1

but the error is still the same.

RE: Abaqus, distributions of thicknesses and plies

It should work if you check this option ("Do not use parts and assemblies in input files") and then export and edit the input file.

RE: Abaqus, distributions of thicknesses and plies

(OP)
@FEA way
I also tried to check the box of: 'Do not use parts and assemblies in input files' but, again, nothing changed.

RE: Abaqus, distributions of thicknesses and plies

Can you attach the input file written this way (and then edited as we discussed before) ?

RE: Abaqus, distributions of thicknesses and plies

(OP)
@FEA way
I have submitted the .inp file you just gave me, and I received the same error as before, plus a new one:
1) Unknown assembly level element set SETVAT1.
2) AbaqusException: Invalid variables are specified in an output request. An output request cannot be created in a step where some variables are invalid. This occurred while creating an output request for variables NT, U in step buckling_step.
The model "SSSS-0000-0000VAT_simplified_v2" has been imported from an input file.
Please scroll up to check for error and warning messages.

RE: Abaqus, distributions of thicknesses and plies

Try running this directly from the command line instead of importing to CAE (inp import may not work properly in some cases).

RE: Abaqus, distributions of thicknesses and plies

(OP)
@FEA way
Excuse me, which are the command lines to open directly the .inp file in Abaqus? Thank you.

RE: Abaqus, distributions of thicknesses and plies

Open the command window in the location of the input file (on Windows you can use Shift + RMB and then select "Open command window here" or "Open PowerShell window here", depending on the system version). Then type the following command:

abaqus job=input_file_name interactive

This will run the analysis and generate output files, including odb file with results (you can open it in Abaqus/Viewer).

RE: Abaqus, distributions of thicknesses and plies

(OP)
@FEA way
the simulation appeared, but the results are different from the version I used. I will check deeper. Thank you very much for you help!

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